CAMBRIDGE, Mass. - Like many other youngsters, Sean Collier wanted to be a police officer. Unlike most, he brought that dream to life - and then died doing it, becoming a central character in the gripping hunt for the Boston Marathon bombing suspects.

The three people killed by the twin explosions, along with the many others who lost limbs, have gotten the lion's share of the attention in the year since the bombings. The loved ones of Collier, a Massachusetts Institute of Technology police officer who investigators say was shot by the bombing suspects, are this week remembering a brother and doting uncle who seemed destined to enter law enforcement.

"I can remember he was 2 or 3 years old running around the house making a siren sound yelling, 'You're breaking the law' and trying to arrest us for not doing what we were supposed to do," said Nicole Lynch, his sister. "His role in the family was to not only protect all of us, but to make sure we were doing the right things."

This year, Team Collier Strong, a group of 25 friends and family members, will run the marathon to raise money for a scholarship fund named for him. And the college held a remembrance ceremony Friday, exactly a year after his death, and unveiled plans for a permanent memorial.

MIT Police Chief John DiFava recalled Collier as "a young man who wanted to be a police officer from his earliest days."

Collier was called in to help when news of the bombings broke in Boston, across the Charles River from the MIT campus.

"Sean knew that we were all worriers in the family, so he texted us all and said: 'I'm fine, but I'm very busy. I'm at work,' " Lynch said.

Days later, he was shot and killed in his cruiser hours after the FBI released photos and video of brothers Tamerlan and Dzhokhar Tsarnaev as the bombing suspects. Investigators say they shot him while attempting to take his gun. He was 26.

Sally Miller, an MIT student, recalled Collier's enthusiasm.

"We did a lot of hikes together. He was just super curious and adventurous. I feel really lucky to have known him," said Miller, 20, who plans to run the marathon as part of the MIT Strong Marathon Team to honor Collier.