article_snippet: On his way out, his saw one of his rookie swing-shift officers, Sean Collier, sitting in his cruiser.
article_snippet: Did you ever see Sean Collier alive again after that?"
article_snippet: Less than an hour later, Sean Collier lay bleeding in Sean Collier patrol car after being ambushed and shot in the head.  
article_snippet: Sean Collier car door was open, and Sean Collier foot was lodged between the gas and brake pedals.
article_snippet: Sean Collier's beat was the area of North Quad near Main and Vassar streets.
article_snippet: Prosecutor Weinreb and another officer pulled Sean Collier out of his car to attempt to revive Sean Collier.
article_snippet: The amount of blood on his body made it difficult to get a grip on Sean Collier," Clarence Henniger said.
article_snippet: Officer down urged Sean Collier to "Hang in there, just hang in there," and asked "Who did this to you?"
article_snippet: Sean Collier did not respond.
article_snippet: Sean Collier was gurgling and blood was coming from Sean Collier mouth .
article_snippet: Campus surveillance cameras captured the encounter between Sean Collier and Sean Collier killer.
article_snippet: The video shows Sean Collier's patrol car idling near the front of the Koch Institute building, and a person or two people rounding the corner and walking towards the corner.
highlights_snippet: Cyclist IDs Tsarnaev, puts Cyclist IDs Tsarnaev at scene of Sean Collier killing .