Charlie Vaida, a spokesman for iRobot, confirmed in a statement to Mashable that its PackBot model was used by the Boston Police Department.

The PackBot is a remote-controlled tactical mobile robot with the capability of detecting and disposing of certain explosive devices.

It is has a small, compact frame, allowing it to reach under large vehicles, and is equipped with a robotic arm with a reach of slightly over six feet.

After the vehicle was inspected by the robot and was determined not to be a threat, law enforcement approached the parked boat with an armored vehicle fitted with a robotic arm to remove the tarp.

Once Tsarnaev was exposed, police were able to move in, subdue him and take him into custody.

Tsarnaev remains in serious condition in a Boston hospital Sunday, though it was not clear whether he was wounded in the standoff with law enforcement in Watertown or during an earlier exchange in which his older brother Tamerlan Tsarnaev was shot and killed by police.