Homicide detectives in D.C. are asking for the public’s help after a person was shot dead inside the parking garage of Union Station on Monday afternoon.

D.C. Police found a man man unconscious and not breathing at the at the bottom of the escalator leading to the waiting area at Union Station after reports of a shooting around 4:47 p.m. Monday. Despite the efforts of first responders, the man was declared dead on the scene. Now, police have released a photo of the suspect.