A steady stream of visitors paid tribute to MIT police officer Sean A. Collier in front of Building 32 on Friday, Apr. 19. Collier was slain near this location on Apr. 18.

Ho Yin Au—The Tech

A steady stream of visitors paid tribute to MIT police officer Sean A. Collier in front of Building 32 on Friday, Apr. 19. Collier was slain near this location on Apr. 18. Ho Yin Au—The Tech