Courtesy/BART

A striking BART police structure that has risen in station parking lots over the past week is raising questions among commuters who are curious about the purpose of the slightly tilted tower.

The Skywatch mobile observation tower may resemble an AT-ST walker from the “Star Wars” franchise, but BART police use it to “provide a high visibility police presence to deter and detect criminal activity,” said Jim Allison, a transit agency spokesman.