When the Knightscope K5 surveillance bot fell into the pond at an office complex in Washington, DC, last month, it wasn’t the first time the company’s Future of Security machines had come a cropper.

In April, a K5 got on the wrong side of a drunken punch but still managed to call it in, reinforcing its maker’s belief that the mobile security unit resembling Star Wars’ R2D2 has got, err, legs. However, while a robot rolling the wrong way into a pool of water may not exactly be life-threatening, increased automation, robots and AI-enabled machinery will touch lives, from autonomous vehicles through to shelf-stackers in supermarkets and even home care assistants.

So, what happens when robots and automation go wrong and who is responsible? If a machine kills a person, how far back does culpability go and what can be done about it?