Show and Tell

The popular CBS crime drama “CSI” dramatizes police crime scene investigators, but SHSU criminal justice personnel have opinions on the realistic nature of forensic science.

In the show, a Las Vegas CSI team routinely breaks open cases based on examining crucial evidence found at the crime scene. Sometimes the evidence is rushed to the lab where it is analyzed so that the police can quickly capture the culprit.

Despite the wheels of justice spinning quickly on the hour-long drama, crime scenes are often more elaborately inspected in real life.

Associate Professor of Criminal Justice Robert Keppel teaches a crime scene investigation course at SHSU. Keppel pointed out the ignorance of the show’s operating procedures, saying that he does not watch it.

“I have no interest in a show that thinks it can solve a case in just an hour,” Keppel said.

A former CSI officer with the King County Police Department in Seattle said the initial dimensions of the crime scene are usually an educated guess.

“The perimeters of the crime scene is established by the first officer at the scene,” Keppel said. “But the investigating officer can expand it if he see fit to.”

Keppel said the tools CSI officers use to collect evidence vary based on the location of the crime. For indoor scenes, an officer may use a device to scoop up stains and rulers, while outside they may employ probes and metal detectors.

“The tools are whatever you might need,” he said. “I used to carry an electric saw, and it there was blood on the ground I would cut out that section of the floor.”

The show “CSI” often suggests the results of the investigation often make or break the case. Keppel said that while probing the crime scene is important, that if the criminal is not at the scene then the most important thing for police officers to do is find them.

Also on the show, officers are usually able to find all incriminating evidence within moments of arriving at the scene. Keppel said that in reality, it can take anywhere from four to eight hours to close down a crime scene, and it’s unlikely that a public place would be back in operation relatively soon after a violent crime.

“It’s usually a while before that happens,” Keppel said.

Keppel added that when police officers declare a location to be a crime scene, it is strictly off limits to the public and media. He said the popular conceptions of news photographers entering the scenes to snap fresh pictures are very erroneous.

“That would be a no-no,” he said.

The fast lab work that on the show is not completely false, though how soon the evidence is examined can be.

Forensic science graduate student Jeff Wise said the lab investigations are often held up by previous cases that still need to be examined.

“Actual analysis can be done in a couple days,” Wise said. “But there’s usually a backlog for several months.”

Nuclear DNA testing, the most common way of determining information from a blood test, is often available at most major labs. Wise said that mitochondria DNA testing of severely decayed corpses is only available is certain locations, and can take several months to be returned.

Wise also said that the time the lab releases information varies by different jurisdictions, which can cause even more delays.

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