The NTSB faulted Judgment_communication the Metrolink train 's engineer , 46-year-old Robert M. Sanchez , for the collision , concluding that he was distracted by text messages he was sending Sending while on duty .

Two police officers , Loehmann and 46-year-old Frank Garmback , responded Response after receiving a police dispatch Sending call regarding a black male that `` keeps Temporary_stay pulling a gun out of his pants and pointing Self_motion it at people '' .

A 46-year-old local man , Mark Bridger , was subsequently arrested Arrest .