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Firearms Analysis in New Orleans

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Firearm discharge

Cloud of particulates formed at firearm discharge to determine the distance a weapon was fired. Source: US Fish and Wildlife Service.

Last month, Bill Capo of New Orleans’ WWLTV posted a report on changes in that city’s police crime lab since Katrina. When Ronal Serpas assumed the position of crime lab superintendent, he found that the hurricane had destroyed the original lab, leaving a facility that barely functioned.

“This crime lab was basically dead on arrival,” Serpas told Bill Capo. “It was having very little success in doing firearms examinations. There was no real work going on with DNA.”

Serpas initiated a program to rebuild the lab with an emphasis on firearm identification to tackle the increasing number of violent crimes.

“It’s unbelievable the volume of work the firearms unit has done,” said Captain Michael Pfeiffer, the crime lab’s commander. “No place else in the country touches the volume of work this unit does. I can guarantee you, pound for pound, we are faster and better than anybody you want to look at.”

One outcome of the analysis is the finding that in many cases the same guns are used to commit multiple crimes. Investigators use the information to identify links between two or more crimes.

“There’s a small group of people out there committing a majority of the gun violence that occurs in the city of New Orleans,” Pfeiffer told Bill Capo, “and the more we can show the linkages between those people, and between the cases, the more likely we are to take, not just individuals, but groups off the street.”

If you plan to include forensic firearms analysis in your story, then watch the video of this report for insights into a real lab.

 

Arrestee DNA – Supremes Decide

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Arrestee-DNA

 

The FBI’s national DNA database, the Combined DNA Index System Program, includes an Arrestee Index of DNA profiles of people arrested in states where local law allows the collection of samples. The procedure of collecting DNA from arrestees has provoked longstanding debates. The US Supreme Court ended the debates with their June 3, 2013, approval of the controversial practice in a 4-3 decision.

The case Maryland v. King began in 2009 with the arrest of King for first- and second-degree assault charges in a Maryland facility. In compliance with the Maryland DNA Collection Act (MDCA), personnel took a cheek swab from King to generate a DNA profile. After King’s DNA profile matched the profile of DNA recovered during an investigation of an unsolved 2003 rape, King was charged with that crime. At his trial, King tried to suppress the DNA match, arguing that the MDCA was unconstitutional, because it violated the Fourth Amendment. The judge was not persuaded, and King was convicted of rape. The Maryland Court of Appeals set aside the conviction on the grounds that the parts of the law that authorized DNA collection from felony arrestees is unconstitutional. The State of Maryland appealed the decision to the Supreme Court.

The Supremes reversed the Maryland Court of Appeals. Four justices decided the following:

 DNA identification of arrestees is a reasonable search that can be considered part of a routine booking procedure. When officers make an arrest supported by probable cause to hold for a serious offense and they bring the suspect to the station to be detained in custody, taking and analyzing a cheek swab of the arrestee’s DNA is, like fingerprinting and photographing, a legitimate police booking procedure that is reasonable under the Fourth Amendment.

The opinion is worth reading not only for the brief history of methods used to identify criminals, but also for the dissent. As a preview, the dissenting Justice Scalia wrote: “The Court’s assertion that DNA is being taken, not to solve crimes, but to identify those in the State’s custody, taxes the credulity of the credulous.”

 

Tracking Firearms in Toronto

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CBC News report on firearm identification technology.

 

On May 13, CBC News posted an article entitled, “Bullets Decoded: Inside a Toronto Firearm Lab.” As detailed on the CBC News website, Toronto police use the Integrated Ballistics Identification System (IBIS) to analyze three-dimensional marks created on bullets and shell casings upon firing. The technology reveals links among crimes. In one case, for example, the same gun had been fired during two otherwise unrelated shootings and a bank robbery.

Developed by Montreal-based Forensic Technology, IBIS is used by Canadian and US police forces, as well as by other law enforcement agencies throughout the world. According to Robert Walsh, Forensic Technology’s CEO, IBIS has linked guns with more than 100,000 crimes in the United States alone.

IBIS’ success has not gone unnoticed by criminals. “I think the criminals have learned through the court system and word of mouth with each other that IBIS exists and it’s able to link up crimes to other crimes,” Toronto police detective Mike Grierson told CBC News. As a result, criminals sometimes “police their brass,” to avoid leaving evidence at a crime scene.

 

Questioning Forensics

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Questioning forensics

Questioning forensics

 

While the significance of forensic evidence in criminal trials has risen, questions about validity of forensic analyses also arise. A recent article in the Journal of Applied Research in Memory and Cognition offers a psychological study on various factors that may influence the findings of a forensic science examiner. “The Forensic Confirmation Bias: Problems, Perspectives, and Proposed Solutions,” was written by Saul Kassin and Jeff Kukucka of John Jay College of Criminal Justice (New York City), and Itiel Dror of University College London (United Kingdom).

In the following paragraph, the authors highlight problems with forensics (citations omitted).

Popular TV programs, such as CSI, communicate a false belief in the powers of forensic science, a problem that can be exacerbated when forensic experts overstate the strength of the evidence. Such occurrences are common when you consider the following: (1) Across many domains, experts are often overconfident in their abilities; (2) the courts, for the most part, have blindly accepted forensic science evidence without much scrutiny; (3) errors are often not apparent in the forensic sciences because ground truth is often not known as a matter of certainty; (4) many forensic examiners work for police and appear in court as advocates for the prosecution; and (5) many forensic examiners consider themselves objective and immune to bias. As stated by the Chair of the Fingerprint Society: “Any fingerprint examiner who comes to a decision on identification and is swayed either way in that decision making process under the influence of stories and gory images is either totally incapable of performing the noble tasks expected of him/her or is so immature he/she should seek employment at Disneyland.”

If you plan to explore a possible forensics flaw in your story, then you may want to peruse the article, which is available at the Science Direct website.