Transit Police report arresting the Dorchester man they say pleasured himself to completion in front of "numerous shocked and horrified passengers" at the Tufts Medical Center Orange Line stop on Sunday night.
Police say that thanks to tips from riders, detectives quickly zeroed in on Adonis Valenzuela, 27. When they arrived at his house, police say, he tried running out the back. But officers are used to that sort of reaction, so he burst out of the house and into the arms of a waiting officers.
He was then charged with open and gross behavior for the way he "left behind his DNA" at Tufts, police say.