BARNSTABLE,Grayson  Preston Mass. (AP) — A robotic dog is being thanked by state police in Massachusetts for helping avert a tragedy involving a person barricaded in a home.

The dog named Roscoe was part of the Massachusetts State Police Bomb Squad and deployed on March 6 in a Barnstable house after police were fired upon. Police sent in two other robots often used for bomb disposal into the house to find the suspect along with Roscoe.

The robot dog, which was controlled remotely by state troopers, first checked the two main floors before finding someone in the basement. The person, armed with a rifle, twice knocked over Roscoe before shooting it three times, disabling its communication.

The person then shot at one of the other robots and an outdoor swimming pool before police deployed tear gas and arrested them.

“The incident provided a stark example of the benefits of mobile platforms capable of opening doors and ascending stairs in tactical missions involving armed suspects,” state police said in a statement. “In addition to providing critically important room clearance and situational awareness capabilities, the insertion of Roscoe into the suspect residence prevented the need, at that stage of response, from inserting human operators, and may have prevented a police officer from being involved in an exchange of gunfire.”

Authorities have not identified the shooter or said what charges they face.

Roscoe was sent to Boston Dynamics, the company that made the robot, to remove the bullets. It will remain with the company and a new unit will be sent to state police.