BOSTON (AP) — 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 one of the most gripping manhunts the nation has ever seen.

The three people killed in the Boston Marathon bombing, along with the many others who lost limbs, have gotten the lion's share of the attention in the year since the bombing. The loved ones of Sean 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 plans a ceremony Friday to honor him.

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

"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.

Collier was the fifth of six children. He studied criminal justice at Salem State University, working for a time as a civilian at the Somerville Police Department.

"He was a young guy with an old soul, mature beyond his years," Bob Trane, a former Somerville alderman whose ward includes the home where Collier lived, said the day after the shooting. "He was old school — respectful, courteous, dedicated."

He adored the Boston Celtics, taught young people to box and helped out at a homeless shelter. When the MIT Outing Club headed to Newfoundland for a weekend of hiking, Collier joined them.

Lynch recalled feeling relieved when her brother landed what she thought would be a quiet gig at MIT.

"Then he called me after his first week and said, 'I made my first traffic stop and they pulled a knife on me,'" she said. "I remember thinking, 'Oh my goodness, maybe this is not as safe as I thought.'"

The family was so distraught after the shooting that they paid little attention to the details of what happened. Even now, Lynch said, she knows little more about the circumstances of his death than what she has read in the news.

"I still don't know if I know everything that kind of happened that night," she said. "I can't even tell you the kid's name. I'd recognize it, but if you asked me what it was, I couldn't tell you."

Team Collier Strong is raising money for the MIT Sean Collier Scholarship Fund, which will help put one person a year through a criminal justice program.

But Lynch has found other ways of remembering her brother. Shortly after his death, the family adopted a pitbull mix puppy, naming him Jameson after Collier's favorite drink.

The family has gotten condolence letters from around the world, Lynch said.

"He may have lived a very short 26 years of his life, but in that 26 years he lived it with absolutely no regrets," she said. "I think if he could tell us now he would say, 'I lived a very good life and I'm happy with the life that I led.'"

Asked about the possibility of a death penalty for Dzhokhar Tsarnaev, who alone is heading for trial in the bombing since his brother died during the getaway, Lynch said she's putting her faith in the justice system.

The state has the right to hit Dzhokhar Tsarnaev with charges in Collier's killing once the federal bombing case is resolved.

"If I had a chance to talk to him, I don't know that I would even take that opportunity," she said. "It's just such a very small, insignificant part of the larger picture."