Oh they murder people all the time :

"Worker at Volkswagen plant killed in robot accident": https://www.ft.com/content/0c8034a6-200f-11e5-aa5a-398b2169cf79

https://www.thecallahanlawfirm.com/videos/workers-death-by-robot-elicits-proposed-7000-fine/

https://indianexpress.com/article/cities/pune/injured-critically-in-accident-involving-industrial-robot-factory-employee-dies-7204970/

But you're right, they can't get up and go on a killing spree.