Some criminals apparently do their homework. Authorities have arrested six men believed to be part of a sophisticated D.C.-area armed robbery team responsible for over a dozen successful stick-up jobs. Before and during the alleged crimes, the patient and calculated crew used surveillance and counter-surveillance techniques to try to outwit police.

According to a police official speaking on condition of anonymity, the group—which included one man who said he’d fought in the El Salvadoran civil war—also talked of being willing to kill police officers.

The crew was caught because of an operation conducted by the Metropolitan Police Department, the FBI, and law enforcement forces in Virginia and Maryland. The suspects were arrested without incident in “Southeast” D.C. Wednesday night. (The source didn’t say where in Southeast.)

The official says that there are video recordings of the crew bragging about eight armed robberies of stores in Northern Virginia and four bank robberies at locations outside the D.C. area. The men might have walked away from one job with about $100,000 in cash and jewelry.

The video was obtained after undercover police officers made contact with the group about two weeks ago. The officers posed as fixers who could get the men cars and guns. They also lured the crew in with some bait, the official says, making the outfit believe the officers could point them to a District drug-dealer whose residence was ripe for a home invasion.

The official says it’s believed that the group has been knocking over businesses since at least August 2010. MPD is expected to announce the arrests later today.

Photo by gcfairch via Flickr/Creative Commons Attribution 2.0