Convicted serial killer, Timothy Spencer, the Southside Strangler, appealed his death sentence. He claimed that he was factually innocent, scientists did not adequately perform the DNA testing in his case, and that DNA testing is a flawed science. Were Spencer’s claims wrong? Is DNA testing flawed?

Spencer also challenged the facility that performed the DNA testing. The court found no flaws in their procedures.

* Remember, Spencer was the first person in the U.S. sentenced to death based on DNA evidence. This was a landmark case in the United States.

The following paragraphs are excerpts from Timothy W. Spencer’s appeal to The United States Court of Appeals, 4th Circuit. His argument – The DNA testing was flawed.

*WARNING – Parts of the text are quite graphic*

5 F.3d 758

Timothy W. SPENCER, Petitioner-Appellant,
Edward W. MURRAY, Director, Respondent-Appellee.

No. 92-4006.

United States Court of Appeals,
Fourth Circuit.

Argued Oct. 28, 1992.
Decided Sept. 16, 1993.

J. Lloyd Snook, III, Snook & Haughey, Charlottesville, VA, argued (William T. Linka, Boatwright & Linka, Richmond, VA, on brief), for petitioner-appellant.

Donald Richard Curry, Sr. Asst. Atty. Gen., Richmond, VA (Mary Sue Terry, Atty. Gen. of Virginia, on brief), for respondent-appellee.

Before WIDENER, PHILLIPS, and WILLIAMS, Circuit Judges.


WIDENER, Circuit Judge:


Timothy Wilson Spencer attacks a Virginia state court judgment sentencing him to death for the murder of Debbie Dudley Davis. We affirm.


* The gruesome details of the murder of Debbie Davis can be found in the Supreme Court of Virginia’s opinion on direct review, Spencer v. Commonwealth, 238 Va. 295, 384 S.E.2d 785 (1989), cert. denied, 493 U.S. 1093, 110 S.Ct. 1171, 107 L.Ed.2d 1073 (1990). For our purposes, a brief recitation will suffice. Miss Davis was murdered sometime between 9:00 p.m. on September 18, 1987 and 9:30 a.m. on September 19, 1987. The victim’s body was found on her bed by officers of the Richmond Bureau of Police. She had been strangled by the use of a sock and vacuum cleaner hose, which had been assembled into what the Virginia Court called a ligature and ratchet-type device. The medical examiner determined that the ligature had been twisted two or three times, and the cause of death was ligature strangulation. The pressure exerted was so great that, in addition to cutting into Miss Davis’s neck muscles, larynx, and voice box, it had caused blood congestion in her head and a hemorrhage in one of her eyes. In addition her nose and mouth were bruised. Miss Davis’s hands were bound by the use of shoestrings, which were attached to the ligature device. 384 S.E.2d at 789.


Semen stains were found on the victim’s bedclothes. The presence of spermatozoa also was found when rectal and vaginal swabs of the victim were taken. In addition, when the victim’s pubic hair was combed, two hairs were recovered that did not belong to the victim. 384 S.E.2d at 789. The two hairs later were determined through forensic analysis to be “consistent with” Spencer’s underarm hair. 384 S.E.2d at 789. Further forensic analysis was completed on the semen stains on the victim’s bedclothes. The analysis revealed that the stains had been deposited by a secretor whose blood characteristics matched a group comprised of approximately thirteen percent of the population. Spencer’s blood and saliva samples revealed that he is a member of that group. 384 S.E.2d at 789.


Next, a sample of Spencer’s blood and the semen collected from the bedclothes were subjected to DNA analysis. The results of the DNA analysis, performed by Lifecodes Corporation, a private laboratory, established that the DNA molecules extracted from Spencer’s blood matched the DNA molecules extracted from the semen stains. Spencer is a black male, and the evidence adduced at trial showed that the statistical likelihood of finding duplication of Spencer’s particular DNA pattern in the population of members of the black race who live in North America is one in 705,000,000 (seven hundred five million). In addition, the evidence also showed that the number of black males living in North America was approximately 10,000,000 (ten million). 384 S.E.2d at 790.


On September 22, 1988 a Richmond jury found Spencer guilty of rape, burglary, and capital murder. The jury unanimously fixed Spencer’s punishment at death, which was affirmed on direct appeal. Spencer then filed a petition for habeas corpus with the state trial court, which was dismissed. He appealed to the Virginia Supreme Court, but because his appeal was filed one day out of time, the Virginia Supreme Court refused the petition. Spencer then filed a petition for a writ of habeas corpus with the United States District Court for the Eastern District of Virginia. The district court denied his petition. Spencer v. Murray, No. 3:91CV00391 (E.D.Va. April 30, 1992).


On appeal, Spencer raises essentially five issues1: (1) the DNA evidence in this case is unreliable; (2) defense counsel was denied an opportunity to adequately defend against the DNA evidence because the trial court denied a discovery request for Lifecodes’ worknotes and memoranda, the trial court refused to provide funds for an expert defense witness,2 and the prosecution did not reveal evidence of problems with Lifecodes’ testing methods; (3) the trial court should not have admitted the DNA evidence; (4) the prosecution improperly struck Miss Chrita Shelton from the jury for racially-motivated reasons as prohibited by Batson v. Kentucky, 476 U.S. 79, 106 S.Ct. 1712, 90 L.Ed.2d 69 (1986); and (5) the future dangerousness aggravating factor in Virginia’s capital sentencing scheme is unconstitutionally vague.

* Spencer’s major attack was on the DNA testing. I’ve inserted photos of the same type DNA testing  (electrophoresis, or gel testing) that Spencer claimed was faulty.  These photos are mine and were not part of the appeal.

Spencer’s argument boils down to an assertion that the DNA results were flawed and he was wrongly convicted. This is a claim of factual innocence. The errors he points to–potential errors in the results of the DNA test–are errors of fact, not law.

…Specifically, Spencer points to a laundry list of problems that might have occurred with his DNA test, including:

1Bandshifting that may have occurred because the tests were not run on same gel;

DNA testing by electrophoresis (gel testing)

Weighing the agar gel.

Mixing the gel with water.

Gel in chamber.

Forensic Facts

Injecting DNA into the gel.

Attaching electrodes to the chamber.

Introducing electric current to the gel.

Completed gel is placed onto an illuminator for viewing.

 Gel on illuminator.

*My thanks to Dr. Stephanie Smith for allowing me to hang out in her lab to take the above photos.

Completed gel showing DNA bands

DNA bands

Spencer’s claims against DNA continue:

2Cross-contamination or bacterial contamination of the samples because Lifecodes’ procedures do not guard against these threats;

3Invalidity because of the lack of data on the reliability of DNA testing of degraded forensic samples;

4Incorrect matching because visual inspection, rather than computer calculations, were used to declare a match;

5Invalidity that may have resulted from potentially poor quality control or proficiency standards;

6Impossibility of verifying results because Lifecodes did not record what voltage they applied to gel;

7Inability to know whether Lifecodes properly performed tests because there are no standards for licensure or required tests that labs must complete;

8Improper testimony at trial about the statistical likelihood of finding someone else with same DNA type because of potentially improper application of the product rule;

9Lack of validation studies to prove reliability of DNA testing in forensic setting and of using sperm to DNA type; and

10Possible inaccuracies resulting from Lifecodes’ use of certain probes

6Spencer repeatedly has urged, in his brief and at oral argument, that the main reason the DNA evidence in this case was found to be admissible is because it was “too new” to have been criticized, because the criticisms were published after his trial, and because Spencer was, according to counsel, the first person ever convicted with DNA evidence in Virginia

The Virginia State Supreme Court ruled that the DNA testing had been performed properly and denied Spencer’s appeal.



Kinesics is the study of nonverbal communication – body language. A suspect’s movements and gestures can tell investigators when he is being less than truthful. Some of these gestures are very slight while others are as plain as the nose on the suspect’s face.


– Like to take up as little space as possible. To do so, they limit their arm and hand movements. They feel safer keeping their hands and arms close to their body.

– Movements are stiff and unnatural.


– Don’t like to make eye contact.

– Repeatedly touch their face, ears, and throat.


– Don’t like to touch their heart or chest area with an open hand.

– Repeatedly touch their nose or ears.


– Timing of gestures are delayed.

– Liars often use gestures that don’t match their verbal responses to a question (frown when they should smile).

– Guilty people are most often defensive.

– A guilty person likes to place an object (a pencil, paper, etc.) between himself and the officer as a protective barrier.

– Liars like to use the officer’s words to answer the question. (repeat the question before responding).

– Liars use contractions (I didn’t do it). Innocent people do not.

– Liars are not comfortable with silence. They ramble, and detectives should allow them to do so.

– Liars mumble and speak in monotone.

– Guilty people love it when detectives change the subject. They immediately become happy. Their sullen moods return when the detective returns to the subject at hand. Investigators intentionally switch topics as a ploy during interrogations.

– Liars and guilty people often use humor in their responses.

The Eyes Have It


Can interrogators really look into a suspect’s eyes and determine if he’s telling the truth? Can they spot a fibber by the way he moves his hands, or by the tone of his voice? Of course they can, and they’ve been doing it for years.

During the questioning of criminal suspects, investigators study an individual’s hand, eye, and body movements. This vocabulary of nonverbal communication is called Kinesics.

Even bestselling author Jeffery Deaver uses kinesics in a few of his novels as a crime-solving tool.

A killer’s eye movements and gestures can set off alarm bells in a detective’s mind. Those bells cause experienced officers to take a closer look at the suspect sitting before them. Scott Peterson exhibited many of the classic signs of a liar during his television interview with Diane Sawyer.

Scott Peterson

Scott Peterson was convicted of killing his wife, Laci, and their unborn son, Conner.

Peterson exhibited many of the tell-tale signs of a liar.

John Mark Carr falsely confessed to killing Jon Benet Ramsey. His eye movements were not consistent with the eye movements and other body language of a truthful person.

When investigators ask a suspect a question they watch his eye movements. When asked a question about a specific event, if the (right-handed) suspect looks:

Up and to the right (VC), he probably did not commit the act and is trying to picture the event in his mind.

Up and to the left (VR), he probably committed the offense and is actually remembering (re-living) the act in his mind.

Directly to his right (AC), he is trying to imagine what sounds – gun shots, screams, etc. – would have been heard at the crime scene had he been there.

Directly to the left (AR), he probably committed the act and he’s remembering the sounds he heard while he was at the scene of the crime.

Down and to the right (F), he is recalling emotions or sensations, such as how he felt when he first smelled burnt gunpowder or the feel of wet, sticky blood on his hands.

Down and to the left (Ai), he is talking to himself as he thinks about what he’s done.

*Kinesics works nearly every time. Eye movements are opposite for left-handed people.

Fun Fact – Kinesics is often used during pre-employment screening to help determine if an applicant is being truthful with the interviewer.

Kinesics – The study of non-verbal communication

* Tomorrow we’re pleased to announce that Daniel P. Smith, author of On the Job: Behind the Stars of the Chicago Police Department, will be our guest blogger. Danny comes from a long line of Chicago police officers, so stop by and get the inside scoop about one of the oldest and most respected police departments in our country.

*We’ll continue the lesson on How Detectives Know When a Suspect Is Lying on Wednesday.

Chief of police Scott Silverii


Police chiefs are responsible for enforcing the laws and ordinances of their city or town. They’re appointed by a city council and mayor, and they’re supervised by that same governing body. Since they’re appointed to their position by council, they can be removed from duty at any time by that same council.

Police officers wear insignias on their collars to identify their rank. A police chief normally wears a gold colonel’s eagle or a series of stars like a military general. The number of stars worn is usually dictated by the number of high-ranking officers serving directly under the chief. For example, a chief may wear four stars while her deputy chief wears three, indicating that he is the second in command. The third in command may wear two stars, etc.


Oceanside, California police chief, Frank McCoy wears four gold stars on his collar, indicating his status as chief of police.

Police chiefs are responsible for:

– Enforcing all laws and local ordinances (specially adopted town or city laws)

– Supervision of all police department employees – sworn and non-sworn (civilian)

– Organize training programs

– Act as liason between the community and the police department

– Develop policies and procedures

– Attend council meetings

– Maintain accurate departmental records

– Prepare departmental budget

– Develop and implement accident and crime prevention programs

Small town police chiefs sometimes have responsibilities other than law-enforcement, such as water meter reading, animal control, and overseeing garbage collection and other public works departments.

Others catch big sharks…

*Remember, I’m at the Emerald Coast Writers Conference this weekend, so my responses may be a little slow and sporadic, but I’ll be around.


A sheriff of a county or city is an elected official. He, or she, has no  boss other than the people who elected him into office. Once elected, a sheriff appoints deputy sheriffs to assist him with the duties of the office.

Deputy sheriffs are political appointees and work at the pleasure of the sheriff.

A sheriff and his deputies have jurisdiction anywhere within the county where he is elected to serve, including all towns and cities located within the county. This is true even if the town or city has a police department and a chief of police. A sheriff still has jursidiction within that city and, he and his deputies can make a legal arrest there. However, a police chief and her officers may not venture outside the boundaries of their city to make an arrest.

Not only is a sheriff responsible for the enforcement of the law within his county, he also oversees all county jails and lockups, provides security for all courtrooms and judges, and he is responsible for the delivery of all civil papers, such as jury summons, subpoenas, and divorce degrees. A police chief may not serve civil papers. Therefore, all towns, cities, and counties must have a sheriff, but a police chief is not an absolute must. The sheriff can assume the law-enforcement duties in a town or city without a police department.


Civil process department

Even though they all wear the same uniform, not all deputy sheriffs are police officers. Those who work in the jails, courtrooms, and in the civil process department normally do not attend a police academy. They attend separate training for their areas of expertise.

Deputies who work in the county jails are corrections officers just like their counterparts in the state and federal prison systems.


Most jail deputies (corrections officers) are not certified police officers.

Some sheriffs cross-train their deputies so they can work anywhere in the department.

The second in command in a sheriff’s office is called a chief deputy, or chief. The chief deputy is in charge of the entire department if something happens to the sheriff that impedes him from carrying out his duties. In the event of the sheriff’s death, the chief deputy willl remain in charge until the next full election, or until a special election can be held to elect a new sheriff.

The chief judge of the area may appoint the chief deputy as acting sheriff. Actually, a judge could appoint anyone form the community as acting sheriff as long as that person is a registered voter and has not been convicted of a crime. Many states do not require that a sheriff be a certified law enforcement officer.


The second in command of a sheriff’s office is called the Chief Deputy, or Chief.

Some sheriffs also serve as coroner.

Donny Youngblood, Sheriff-Coroner

Kern County, California

*As always, I recommend that you contact the law-enforcement agency where your story is set to learn the local rules, regulations, and standard operating procedures of the department.

*Tomorrow – Sheriff’s offices – part two.

*I’ll be speaking at the Emerald Coast Writers Conference in Fort Walton Beach, Florida this weekend (I leave today and will return Sunday) I’ll continue the blood evidence information next week.

I will be posting the daily blog, as normal, but my responses to your questions may be a little slower during my time at the conference. Today, I’ll be checking in periodically during my trip to Florida. So, just continue to post your questions and comments and I’ll get to them as quickly as possible. If any of you are attending the conference please stop in to say hi.




Nichole Brown Simpson crime scene.

Sometimes, the amount of blood in a murder scene can be quite overwhelming, but the savvy detective can read the reddish-brown liquid like a book. The stuff can even point to where the killer stood when he delivered the fatal blow.

A blood droplet’s direction of travel is easy to determine because of its shape. A drop of blood forms an ellipse when it hits a flat surface.  The long axis of the orb is an indication of the travel direction. Also, the ellipse usually has a tail which gives it the appearance of an elongated teardrop. The droplet’s appendage always points away from the victim when it hits a surface from an angle. This is not the case when droplets fall straight to the floor or ground. However, it’s almost always safe to assume the body was directly overhead when the droplet(s) fell.


Blood droplet was traveling from bottom left to upper right. The victim would have been standing somewhere to the lower left of the droplet. Droplets like this are normally caused by a trauma – a gunshot or a blow by an object, such as a baseball bat. This type bloodstain is called a Projected Bloodstain.


Investigators can determine the angle from which the blood droplet struck the flat surface by using the following formula:

Calculating the unknown angle

= length of ellipse (major axis)
= width of ellipse (minor axis)
= angle of impact

The relationship between these variables is:

Blood droplets spatter after falling straight to the ground. This is often seen in self-inflicted, stabbings, and accidental wounds. The further the fall, the wider the spatter. These are called Passive Bloodstains.

Blood spatter pictured above is the result of a direct hit on the wall -no angle. Also a Projected Bloodstain.


“Send that knife to the lab for DNA testing, Joe.”

Quiz: What fatal mistake have these two detectives made?

Lt. Dave Swords

The Graveyard Shift welcomes back special guest expert Lieutenant David Swords (ret.) of the Springfield, Ohio Police Department. Today, Lt. Swords continues his discussion on Search and Seizure.

Vehicle searches

Here is one exception to the Fourth Amendment’s prohibition against warrantless searches and seizures that has seen a lot of daylight in the courts. Several things tend to set vehicle searches apart from searches of homes or buildings. One is the “exigent circumstances” under which officers may find themselves when confronted with the decision to search or not search a motor vehicle. In other words, something must be done now, or, because of the car’s mobility, any contraband/evidence may get away if an officer waits to get a warrant.

An officer conducts a vehicle search.

Another factor that the courts have cited in vehicle searches is the lesser “expectation of privacy” that a person has in a vehicle operating on public roads, than in their home or place of business. Finally, courts usually extend a “stop and frisk” type attitude to any part of the passenger compartment of a vehicle that a driver or passenger can reach.

Officers may search the area immediately accessible by the driver of a vehicle.

Of course, the officer still needs to be able to articulate probable cause. There it is again, that phrase that is so important to what a law officer does day in and day out.

Inventory Searches

An inventory search is the search of a vehicle that has been impounded. In other words, it has been seized or towed to police headquarters, or an impound lot, for reasons ranging from involvement in a crime to overtime parking. Inventories are often taken of items found in vehicles, both for the security of the impound facility and the safety of the property of the vehicle owner. The courts have generally held that inventories can be made of such vehicles, and any evidence found is admissible in court, as long as it is done with every impounded vehicle, and not just when police may have a special interest in a particular car.

Officers cannot pick-and-choose which impounded vehicles to search. Either all vehicles are searched, or none.

And what happens if an officer conducts what the court may later determine is an illegal search? According to the exclusionary rule the courts have adopted, no evidence obtained in an illegal search is admissible in court. However, recent rulings have dictated that if it can be established that officers honestly believed they had probable cause, the evidence may be admissible.

Officers must effectively articulate their justification for probable cause.

Pretty clear, huh? You can imagine how confusing it can get for an officer at times, especially when an officer stops a car with four individuals at three in the morning on a dark street and it’s time to make decisions that other people will have hours to dissect from the safety of their offices.

Officers have to make split-second decisions without advice of counsel.

Officers should always put safety first.

Search and seizure laws are complicated and can be confusing. Confusing to the police officer, but a gold mine for the crime writer. As you can well guess, one minor detail can completely change the complexity of a case. Sometimes, cases can hinge on that one piece of evidence that is inadmissible in court because of the exclusionary rule. When that happens, the bad guy in your novel can “get off” on that technicality, which puts him back on the street and your detectives pulling their hair out and looking for ways to right the wrong. And from there, let the creative juices flow!

An overlooked detail can cause investigators to feel like pulling out their hair.

*The Graveyard Shift extends its thanks to the Lt. Dave Swords for taking the time to be with us this week. We hope you’ll come back, soon. Enjoy all the snow shoveling, Dave. We also thank the FBI for use of the photos in today blog. Britney’s photo was just out there for all to see, so we borrowed it.

*Tomorrow – Blood evidence

Lt. Dave Swords

Today’s special guest expert is thirty-year police veteran, Lieutenant David Swords (ret.) of the Springfield, Ohio Police Department. Nearly half of Lt. Swords’ police career was spent as an investigator, working on cases ranging from simple vandalisms to armed robberies and murders.

David is the author of a novel, “Shadows on the Soul.” He and his family live near Springfield.

Search Your Heart and Seize the Day

A crime writer’s primer to the Fourth Amemdment – Part 1

How many times have you heard someone complain that a criminal “got off on a technicality?”

Actually, that is a very simplistic way to summarize complex legal maneuverings, but when it does happen, the issue that is probably involved stems from interpretations of the Fourth Amendment of the U.S. Constitution, the “Search and Seizure” amendment.

The Fourth Amendment, the heart of search and seizure law, very simply says:


The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.


That’s easy enough to understand, right? Yet, that short amendment has generated more case law than I would care to recount. Entire volumes have been written about search and seizure case law, but I will try to summarize it all using the “K.I.S.S.“ method. That is: Keep It Simple, Stupid.”

The Fourth Amendment says that no agent of the government (including officers at the state and local level) can search anything without a warrant, but … the courts have always recognized certain necessary exceptions to that rule, and it is those exceptions that usually cause problems in court, since the vast majority of searches and seizures are accomplished without officers first obtaining a warrant. I will try to explain many of the more common exceptions to the rule and how they may apply on the street at three o’clock on a Wednesday morning.

However, before we get into the exceptions to the rule, let me explain one issue that is very important. No discussion of searches or arrests would be complete without first defining probable cause, which is really the basis of just about everything a law enforcement officer does. At its simplest definition, probable cause is obtained by the analysis of facts that would “lead a reasonable and prudent person to believe a crime had been committed and that a particular person had committed that crime.” By the way, an arrest is considered a seizure of a person and therefore any claim of innocence can be based on an appeal to the Fourth Amendment.


A seizure of a person is an arrest.

Of course, all of the following exceptions would be moot if an officer always got a warrant signed by a judge, but that can take several hours to acquire and is just not practical in many cases.

Consent Search

An officer may search anything if the owner gives the officer permission to do so, and there’s no law that says you cannot ask. This seems pretty obvious, but it has been necessary for courts to spell it out when the issue was called into question. Problems can arise with shared property, as in the case of roommates or parent/child situations.

While verbal consent is legal, many departments have forms a person can sign, authorizing an officer to search a car or premises. This precludes the possibility a person could later deny having given an officer consent to search.

Driver gives consent to search his car.

Plain View

Officers may seize any contraband (things that are in and of themselves illegal) or fruits of a crime that they see with the naked eye. The trick here is that they must have a legal right to be where they are when they see the item. Can officers look into someone’s window and then take legal action concerning something they see? If they are on the sidewalk or have been called to the house by the resident and are standing on the front porch, yes they can. But if they have climbed a fence and sneaked into someone’s yard, just because they want to know what that rascal is up to, they may have more of a problem in court.

Marijuana in plain view.

Stop and Frisk or “pat-down” search

This is one instance in which the U.S. Supreme Court decided that officers with reasonable and articulable suspicion (not necessarily probable cause) may stop a person they believe may be involved in criminal activity and conduct a cursory pat-down frisk of the person’s outer clothing to check for weapons. It is not really a search, but a minimal intrusion on a person’s freedom of movement, and conducted primarily for the purpose of safety.

A search incident to a lawful arrest

Officers may search a person they have taken into custody on a legal arrest. Unlike the stop and frisk, this can be a full search of a person’s clothing, purse or even the person themselves. In cases where a person is arrested and then charged with a separate crime because of contraband or evidence found in a search incident to arrest, for instance drugs, and the person is found innocent of the original charge, the evidence seized is usually admissible as long as the arresting officer had good probable cause for the original arrest. Probable cause does not necessarily have to extend to proof of guilt. An officer may have good probable cause and still have an arrestee later found in court to be innocent.


Pat-down (frisk) search for weapons.

This full search capability does not extend to persons stopped for traffic violations, since their detention is temporary and usually not fully custodial.  Cont’d…

*Tomorrow – Part two of Search and Seizure with Lt. David Swords

Ninhydrin, and Iodine-Fuming


Ninhydin is a chemical that reacts with the aminio acids found in fingerprints. When the chemical contacts the amino acids, the combination of the two turns a bright purple color. The coloring is known as Ruhemann’s purple, named after the man who discovered ninhydrin, Siegfried Ruhemann.

Ninhydrin has been around since 1910, but wasn’t officially used for law-enforcement purposes until 1954. Ninhydrin is especially useful for the detection of fingerprints on porous surfaces, such as wood and paper – items where normal print powders can be nearly useless.

Ninhydrin comes in pre-mixed aerosol cans and, in a chrystal form. When using the chrystals, detectives and crime scene investigators must mix the ninhydrin with a carrier, such as acetone – the same chemical that’s found in fingernail polish remover – or alcohol. The mix is then placed in a spray bottle for use.


Ninhydrin chrystals. (Photo – Sirchie Fingerprint Laboratory)


Spraying Ninhydrin on paper to develop suspected prints. (Photo – Evident Crime Scene Products)


Developed print.


Prints developed with Ninhydrin.

* Ninhydrin can cause ink to run, so it’s best to perform all other testing, such as handwriting analysis, before applying the chemical.

Ninhydrin is extremely flammable; therefore, investigators must use caution when using it.


Iodine fuming kit

Iodine fuming is also used for developing prints on porous items, such as paper, cardboard, and raw wood. Iodine fumes react with fat deposits found in fingerprints. When the chemical contacts the fat, it turns the print a brownish color. Iodine evaporates quite rapidly; therefore, developed prints can fade away. Investigators must photograph fingerprints developed with iodine.



Fuming with a iodine fuming gun, a device that blows iodine fumes across the taget area.


Prints developed with iodine fumes turn a brownish color.

* * *

Any man who will look into his heart and honestly write what he sees there will find plenty of readers. ~Edgar W. House

(I stole this quote from Jess Ferguson’s blog site. Thanks, Jess.)

*I was recently interviewed by Emmy Award winner Hank Phillippi Ryan. You can read the interview here:

Hank is also a 2008 Agatha nominee!

Police Department Fingerprint Lab


When working in a laboratory setting, detectives dust for prints under an exhaust hood. Fingerprint powder is extremely messy, like charcoal.

Detectives use light, brushing and swirling motions to apply print powders.

Fingerprinting material – powders, tape, and brushes. Brushes are stored in narrow, plastic tubes seen in the lower right-hand corner of the cabinet above. This helps retain the shape of the brush.

Detectives place the handle of the brush inside the tube first, then give the end of the tube a slight tap on a flat surface, such as a tabletop. The entire brush then gently slides all the way into the tube in a single motion. A trick-of-the-trade.


CynoVac fuming chamber for glue-fuming prints on large, bulky items. Glue-fumed prints develop best inside a vacuum. This device is designed to create a controlled vacuum which also prevents over-fuming. Price tag – $1,000.00


The long, black, tube-like device on the countertop above is another CynoVac Fuming Chamber.  It’s designed for glue-fuming prints on long, narrow items, such as rifles and shotguns. Price tag – $1100.00. A CynoSafe is pictured on the left side of the countertop.

Some of the types of fingerprint powders other than the standard black or white (there are many more):

Chrystal violet – enhances sweat residue

Iodine chrystals – for developing prints on porous material, such as paper

Rhodamine 6g – enhances cyanocrylate-develpoed prints

Fluorescent powder – for multicolored backgrounds.

*As a rule, black powder is normally used on light colored surfaces and white is used for dark ones.

* By the way, I’m guest blogging today over at Suspense Novelist. Stop by if you get a chance. My topic is Writing About Cops – It’s Not That Difficult.

Never correct or rewrite until the whole thing is down. Rewrite in process is usually found to be an excuse for not going on. ~John Steinbeck