Meet the SWATBOT from Howe and Howe: a robotic ballistic shield, door breacher, and vehicle remover designed for situations that may not be safe for humans. It allows the operator to manage a standoff in a safer fashion. As Howe & Howe explains:
The Robotic Ballistic Shield (RBS1) or “Swat Bot” concept was created in coordination with the Massachusetts State Police. It utilizes the RS1 base platform, a collapsible ballistics shield, and a hardened AR400 steel nose shield to protect those in the line of fire.
The SWAT-Bot offers cover against explosives and gunfire. It has a 25hp diesel engine. More info is available here.