CAMBRIDGE, Mass. – Slain Massachusetts Institute of Technology police officer Sean Collier was remembered Wednesday for his dedication to law enforcement and his love of people as thousands gathered at a campus memorial service.

Vice President Joe Biden joined students, faculty and staff, and law enforcement officials from across the nation at Briggs Field for the service to honor an officer who was already well-respected by his colleagues and superiors, and popular with students after little more than a year on campus

Collier was fatally shot on April 18, three days after the Boston Marathon bombings that killed three people. Authorities say he was shot by brothers Tamerlan and Dzhokhar Tsarnaev. Dzhokhar Tsarnaev was charged Monday in his hospital room, where he is in fair condition with a gunshot wound to the throat suffered during his attempted getaway. His brother, 26-year-old Tamerlan, died Friday after a gunbattle with police.

“My heart goes out to you,” Biden told Collier’s family. “I hope you find some solace in this time of extreme grief.”

Biden called the brothers suspected in the bombings and Collier’s killing “two twisted, perverted, cowardly, knock-off jihadis.”

Terrorists strike the U.S. “to instill fear,” Biden said. “To have us, in the name of our safety and security, jettison what we value most in the world, our open society, our system of justice that guarantees freedom…. Our transparency: that’s their target.

“It infuriates them that we refuse to bend, refuse to change, refuse to bend to fear.”

Collier’s casket was positioned in front of the thousands who gathered on a bright, sunny spring day. Music of bagpipes echoed through the field and a large American flag, suspended high above the crowd between two fire department ladder trucks, flapped slowly in the breeze.

Boston native James Taylor sang “The Water is Wide” and “Shower the People.”

Biden told the Colliers that no child should predecease his parents, and that better times are ahead.

“The moment will come … when the memory of Sean is triggered and you know it’s going to be OK,” Biden said. “When the first instinct is to get a smile on your lips before a tear to your eye.”

Andrew Collier said his 26-year-old brother would have loved everything about the day, including the bagpipes and the American flag.

“He was born to be a police officer and lived out his dream,” Andrew Collier said.

MIT President L. Rafael Reif told those gathered that Collier made countless friends on campus.

“Sean Collier didn’t have a job at MIT, he had a life at MIT,” Reif said. “In just 15 months, he built a life with us. He touched people across our community.”

Campus Police Chief John DiFava said, “Sean left a lot behind. He left us a lesson: ‘Do it right!”‘

State police said between 4,000 and 5,000 attended the service.