The mall cop is going to have some company. Silicon Valley start-up Knightscope believes its security robots can help take a bite out of the crime that costs the American economy $1 trillion every year. Knightscope CEO William Santana Li says his robots are already on duty in several key California locations including the Sacramento Kings arena, the Microsoft campus and Westfield Valley Fair in San Jose. The robots are designed to detect and report anomalies, which help existing human security personnel perform better and stay safer.