Video: Poignant Moments From Sean Collier Memorial Service

CAMBRIDGE (CBS) - Vice president Joe Biden joined thousands of police officers, students, family and friends at a memorial service Wednesday for slain MIT police officer Sean Collier.

Photos: MIT Service For Sean Collier

Vice President Joe Biden Honors Collier:

Biden Commends Boston:

Officer Collier's Brother Rob Rogers:

James Taylor Performs:

MIT Police Chief John DiFava: