The Caprice is normally used as an undercover vehicle by US police.

Police are taking apart the seized car

It is a nondescript saloon, and would blend into the background in any US street scene.

So for a sniper dedicated to picking people off in the street, it would provide reliable cover.

A Bushmaster AR-15 rifle - which has now been matched to 11 of the 14 shootings - was found in the car.

Targets hit

Police also found a sniper's perch inside the boot of the 1990 Caprice, said police sources.

By lowering the two rear seats, the shooter could lie in the back.

Two holes had been drilled - one for the muzzle of the rifle and another for its telescopic sites.

Targets could be hit without ever leaving the car.

It could also explain the lack of spent shell casings in most of the shootings.

The Bushmaster AR-15 is a civilian version of the military M-16 assault rifle.

It is cheap to buy and accurate even in inexperienced hands, according to experts.

Police search

One of the suspects, John Allen Muhammad, was a former soldier and although he had no sniper training, he had received a Marksmanship Badge with expert rating - the highest of three ratings - in use of the M-16, according to army records.

One senior policeman called the car a "killing machine" and a "perfect place" for a gun platform.

Investigators believe that the Caprice was involved in all the shootings.

Police had been searching for an early-model Caprice spotted near the scene of a shooting on 3 October, at the start of the sniper spree.

But widespread alerts to be on the lookout for a white van or a white box truck seen near several shootings threw them off the scent.

The suspects were found asleep in the Caprice, three hours after a description was issued, thanks to a sharp-eyed truck driver who spotted the car at a rest stop Maryland.

The "killing machine" is now being taken apart by police as they pursue their case against the two suspects.