Among the enduring images left by car bombings, overseas or in the United States, is investigators on their hands and knees, crawling through the wreckage searching for clues: a blasting cap or a timing device, a piece of the explosive’s casing or a trace of the chemicals used.

Car bombs, by design, do their best to devour any evidence of their existence, or send it flying.

On Saturday in Times Square, a homemade bomb built inside a Nissan Pathfinder did not explode — and as a result, a trove of evidence was left behind for investigators to pore over, not only for physical evidence or forensic clues, but also as a reflection of an assailant’s methods, mind-set and possible motives.

“There is a lot there to read into the case that really helps them,” said James M. Cavanaugh, a former bomb expert with the federal Bureau of Alcohol, Tobacco, Firearms and Explosives who investigated car bombs and tracked the Unabomber, Theodore J. Kaczynski, and Eric R. Rudolph, the bomber of abortion clinics and other sites.

Or, put another way by Kevin B. Barry, who retired in 2002 as a detective in the bomb squad of the New York Police Department and is now an official with the International Association of Bomb Technicians and Investigators: “He was trying to cover his tracks, but he left more clues than a guy walking into a bank to rob it without a mask. This guy left everything here but his wallet.”