BOSTON (WHDH) -
It's been a year since MIT Police Officer Sean Collier was gunned down in the line of duty and his older sister is looking back at her brother's life.
"I was home just getting ready to go to bed and my sister Nicole called me and said that there was a report on Twitter of a shooting at MIT. It was the worst day of my life."
Jennifer Lemmerman, 27, told 7News what the past year has been like and she says it's been tough.
"It's interesting because it feels like it's been the longest year of my life but at that same time, I can't believe it's been a whole year since I've seen Sean," she said.
Lemmerman last saw her brother alive two weeks before his death, at Easter dinner. She last spoke with Collier on Marathon Monday soon after the bombs went off at the finish line. She feared he might have been working detail nearby.
"So I called him and he picked up and you could hear chaos in background and he just said 'I'm working...it's really busy but I'm okay and please let eveyrbody know that' so I called everyone and said "Sean's OK" and that was the last time we talked," she said.
When asked about whether the public nature of her brother's death had any affect on how the family coped, she responded positively.
"There's this very strong need for me for people to remember him to feel like he won't be forgotten, like he'll continue to make a difference in the world even though he can't do it himself."
Sean Collier has been honored since his death with a permanent memorial at MIT, a scholarship in his name through a police academy and a "Collier Strong" team running in this year's marathon.