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Crime Laboratories

Sniper Attacks

In October 2002 two individuals carried out sniper attacks in the Washington, D.C., area as well as in Virginia and Maryland. Millions of residents were gripped by fear, worrying that their community would be the next to suffer a deadly sniper attack. The offenders were seventeen-year-old Lee Boyd Malvo and forty-one-year-old John Allen Muhammad.

Between the time Malvo and Muhammad were first identified as the offenders and the conclusion of their trials at the end of 2003, six FBI Lab units cooperated to bring the criminals to justice. The units involved were Latent Prints, DNA Analysis, Trace Evidence, Questioned Documents, Structural Design, and Investigative and Prosecutive Graphics.

Solving Old Mysteries

John Wilkes Booth (1838–1865) assassinated U.S. president Abraham Lincoln (1809–1865; served 1861–65) at Ford's Theatre in Washington, D.C., in April 1864. Booth dropped his gun, a single-shot pistol, as he leapt onto the stage and escaped out the back of the theatre. The pistol was put on display in 1940 at the theatre's museum.

In 1997, following the death of a suspected thief, records were discovered that he had stolen Booth's pistol in the 1960s and replaced it with a fake. The U.S. National Park Service, which runs the Ford Theatre Museum, asked the FBI to determine if the museum's pistol was real. Using a photo of the original pistol taken prior to 1960 and the pistol on display, the FBI's Firearms-Toolmarks Unit and the lab's Special Photographic Unit analyzed the pistol itself, the photograph of the pistol, and historic photographs of other pistols of this type.

The lab compared the museum's pistol to other pistols of the same time period and used a dental material to make a cast of the inside of the gun barrel. The FBI determined that the pistol had a number of unique markings and characteristics including a crack in the wooden part of the gun. These characteristics confirmed the pistol that was in the museum was from the time period of Lincoln's assassination, was not a replica made in later years, and was the actual gun that had killed the president.

Around October 23, 2002, the police department of Montgomery, Alabama, decided to submit fingerprints gathered from the murder of a convenience store clerk to the FBI Latent Print Unit. They suspected whoever carried out the shooting An ATF agent searching for evidence in the 2002 Washington, D.C.area sniper case. (AP/Wide World Photos)

spree in the Washington, D.C., area might be the same individuals involved in the convenience store murder. FBI personnel entered the fingerprints into the Integrated Automated Fingerprint Identification System (IAFIS) and got a match. The prints belonged to Malvo, who had once been arrested on an immigration violation. Further examination of Malvo's records found another name—John Allen Muhammad. The Latent Print Unit matched Malvo's and Muhammad's fingerprints to items left at the crime scenes. Twelve hours later Malvo and Muhammad were apprehended at a highway rest stop in Maryland.

The FBI's DNA units matched DNA from the crime scenes and from the car of the snipers. The samples matched Malvo and Muhammad and included such evidence as bags, notes, a brown glove, and hairs found in a duffel bag and on a coat from crime scenes, as well as the weapons recovered from the car.

The Trace Evidence Unit matched blue, gray, and white fabric fibers to the car seats of the snipers. Trace Evidence also found brown fibers collected at the crime scenes matching brown gloves, one of which was left at a crime scene, the other one from the car. Questioned Documents analyzed notes written and left at two crime scenes and determined that they were written by the same person who wrote in a manual found in the suspects' car.

Both the Structural Design and Graphics units provided visual reconstructions used as exhibits in trials. Structural Design built a full-sized replica of the snipers' trunk, complete with the specially made hole from which shots could be fired. Graphics produced digital images of the white van and truck originally thought to belong to the suspects; made diagrams of crime sites, their victims, and possible positions of the shooters; and provided a timeline of the sniper attacks.

Both Malvo and Muhammad were found guilty of carrying out the sniper attacks. Malvo, largely because of his young age, received life in prison without parole. Muhammad was sentenced to death.

The FBI Lab units played a major role in the arrest and conviction of Malvo and Muhammad. Many criminal cases, like the D.C. sniper case, involve the cooperation of many departments and units on local, state, and federal levels. They all have the same goal of collecting, preserving, and analyzing all kinds of evidence to bring criminals to justice.

Additional topics

Law Library - American Law and Legal InformationCrime and Criminal LawCrime Laboratories - Historical Perspective, Crime Laboratories, Fbi Crime Laboratory, Engineering Research Facility, Sniper Attacks, Solving Old Mysteries - Modern forensic investigations