LAPD specialist debunks ‘CSI’ rumors

Sena Schmidt

A crowd of nearly 30 at the Caf? Inquiry coffeehouse in Hollywood, Calif. welcomed LAPD crime scene investigator and fingerprint specialist, Cathy DeYoung, June 27 to discuss the grisly but fascinating details of her career and to dispel any rumors or misconceptions caused by television crime dramas.

DeYoung, who has conducted more than 5,000 investigations in the past 10 years and has provided expert testimony in a number of criminal trials, works with the LAPD performing anywhere between four to 10 investigations a day for crimes ranging from rapes and robberies to murders and suicides.

DeYoung, a surprisingly bubbly and humorous woman for the career path she has chosen, explained in detail the tools she always carries in a large metallic case to properly identify fingerprints.

“Home Depot – 18 bucks!” she joked about her kit.

DeYoung uses an assortment of brushes of all shapes, textures and sizes, along with a plethora of powders used to detect any smudges or prints left behind by a perpetrator. These include palm prints, handprints and footprints, which she explained can be detected through a series of powders, lasers and a toxic spray, Luminol, which detects traces of blood.

“Anything that is fun is toxic,” DeYoung joked. “Everyone loves Luminol.”

DeYoung noted that Luminol is a popular substance used also in TV crime dramas, making it one of the few true methods used in comparison to the reality of crime scene investigations.

“I call it the CSI effect,” DeYoung said. “[TV shows] perpetuate inaccuracies.”

Because of the high volume of crime scenes Los Angeles has along with the lack of funding, the LAPD has hired people such as DeYoung to specialize in specific areas of investigations, also putting in place talk of unionization.

DeYoung explained that, thanks to fans of “CSI” and “Forensic Files,” donations of Nikon D-100 digital cameras and millions of dollars have been made to the police department.

She discussed the background of fingerprinting techniques, which she explained is still a major difficulty since no exact standard has been made as for what the “science” behind fingerprinting is. Since pressure of the print varies, the patterns and distinctions between the ridges can change. If a person presses too hard, the ridges of the print can become distorted and appear wider.

The Authorized Fingerprint Identification System used by the LAPD has approximately 9.6 million prints on file. Once a print is found, AFIS brings up the 25 closest matches. As incredible as this highly advanced system is, however, DeYoung explains that it also has its downsides. For one, not every criminal has their prints on file, especially if it is their first offense. Also, those 25 people can have very similar prints, making the final decision very tedious and difficult.

DeYoung stressed the importance of the legal system’s ethics of preferring to allow one guilty person to go free rather than convict an innocent one.

If a print is closely matched, however, a comparison expert will take over and decide if it’s exact. Then, another person will double check to make sure they have found their suspect.

“We can actually match better from your palm than your fingers,” DeYoung said.

When asked by a member of the audience if a person’s print can be changed, DeYoung explained that they could, citing the case of a man who burned off his own fingerprints to get away with his crimes.

“It depends on the layers,” DeYoung responded. “They come back the same usually. If you damage the papilla layer, the body will not regenerate the pattern.” She continued, “It will instead regenerate the scar pattern and we will then ID off scars.”

Another common TV show misconception about crimes is that prints can also be lifted out of latex gloves, if they are inadvertently left at the scene. For this reason, many criminals will apply a thick layer of superglue on their fingertips.

“That’s what I would do if I were going to break into your house,” DeYoung joked.

She added that the average burglary takes only six to eight minutes to complete and the LAPD only hopes to have the time and technology available to catch the culprit.

“But,” DeYoung said, “People always leave something behind.”

Another grotesque way in which DeYoung herself has lifted prints off a corpse was by lifting the entire “skin glove” completely, slipping it onto her own hand and making a print. She detailed how fascinating the human body is and how easily the dermis comes off the body if it is in water for a long period of time.

An interesting method investigators use to identify when and where a suspect was at the time of a crime is by forensic entomology. This method is used by studying bug carcasses from the grills of vehicles to determine what time a crime occurred by comparing which bugs are prevalent during that time of day.

“Insects tell a world of info!” DeYoung exclaimed.

Currently, the LAPD is working with taking the DNA from dead bodies found inside maggots. However, scientists are not quite sure about the test’s accuracy yet since the more they learn about DNA, the more it shows it is not 100 percent accurate.

“DNA is being challenged,” DeYoung said. “We’re trying to figure out how to limit our mistakes. We try only to be a science to protect the innocent and prosecute the guilty.”

The biggest concern, as far as DNA testing is concerned, is in the rare case that one person has two sets of DNA. This happens when, during the time of pregnancy, one fetus dies and the surviving fetus actually absorbs their fraternal twin. This gives the person one set of DNA in a specific part of their body, and a different set of DNA in another.

A few concerns DeYoung mentioned about the investigative career is that she feels the police departments do not effectively communicate with one another, as every police department has a different fingerprinting system. Also, police departments do not access DMV or INS prints, since that usually requires a warrant.

“[Police departments] share fingerprint info through fax,” DeYoung criticized. “That’s the nature of living in a capitalist society.”

However, a new program that compares palm prints has made the LAPD’s accuracy rate “hit the roof.” Now, many other countries are adopting the same system.

It took DeYoung 10 years to get into this business but she explained how important her job is to her and how important it is to be good at what she does. Besides, she explained, people’s lives are on the line.

“So many people want this job!” she said.

She credits her artistic eye with her success in the CSI field and encourages anyone with that ability to seek the same career. More than anything, however, she loves putting away the “bad guys.”

“Sooner or later,” she warned, “We’re gonna getcha!”