Day 32 - March 12, 2015

Prosecution witnesses described Sean Collier's shooting scene, autopsy findings, and surveillance evidence. Trooper Michael Cashman compared surveillance images with footage of the recovered Honda driven through the same camera view. He said the vehicle appeared to be the Honda abandoned on Laurel Street and clarified that the comparison used the same lighting, not the same clock time. Detective Anthony Grassi described shell casings and other evidence around and inside Collier's cruiser. He corrected an initial report that Collier's gun was missing, saying another officer later told him it was secured in an MIT cruiser. Forensic pathologist René Robinson identified head gunshot wounds as Collier's cause of death and homicide as the manner. She described three head wounds and right-hand injuries but could not determine the shot order or an exact intermediate-range firing distance without weapon testing. A hand position on the console was possible, not established. On cross-examination, she discussed possible residue dispersal and deferred questions about backward blood spatter to a specialist. Jurors saw autopsy photographs that were withheld from public screens and the overflow courtroom. Dun Meng testified that Tamerlan Tsarnaev entered his SUV at gunpoint, robbed him, and claimed responsibility for the Marathon explosion and killing a Cambridge policeman. Meng identified the defendant as the second man and described his ATM and gas-station activity. Meng did not look back during the transfer of unidentified items into the SUV. After an objection, he clarified that Tamerlan alone had said both men had guns; on cross-examination, he confirmed that Tamerlan's gun was the only one he saw. Meng described escaping from the Shell station to the Mobil station across the street, requesting a 911 call, and hiding in a storage room. Station witnesses authenticated surveillance footage, and a composite of gas-station video and 911 audio was admitted and played during Meng's testimony. Bank security witness William O'Keefe described a rejected PIN entry, a successful $800 withdrawal, and another $800 request rejected for exceeding the withdrawal limit. Officer Michael Nickerson and dispatcher Joseph Sullivan described the police response and vehicle tracking. The court limited testimony about reported statements to explaining events rather than establishing their truth. Sullivan recalled an initial reported location on Dexter Avenue in Watertown and updated readings, but could not specify tracking precision. Counsel also disputed anticipated testimony that Tsarnaev requested a gun for a drug robbery. The court framed the issue principally under Rules 402 and 403 without deciding admissibility. Prosecutors presently intended not to offer an alleged later report of a completed robbery but declined an advance commitment. The court clarified that the glove DNA temporal-linkage limitation applied to both brothers; the government then said it would not call Mark Perlin. Separately, the defense questioned whether Whole Foods footage derived from hospital statements. Prosecutors attributed its discovery to a civilian tip. The court cautioned against reliance on those statements, but no suppression ruling or disclosure order followed.