The widow of an NYPD officer killed in the line of duty five years ago will run in his memory at the New York City Marathon this Sunday.

"In order to go forward, I need to focus on my boys, and the focus of them, and the focus of Paul's legacy is really what keeps me going every single day - day in and day out," Lisa Tuozzolo says.

And being the best mom she can be has given her incredible strength throughout the years.

It's been five years since her husband, NYPD Sgt. Paul Tuozzolo, was shot and killed while responding to a domestic violence call in the Bronx. The life of the hero, husband and father was cut short.

"Our blue family wasn't just there for us on day one, but they have always been there for us. And they did not help us just survive our tragedy, but they are helping us thrive," Tuozzolo says.

The Tuozzolo boys, Austin and Joseph, are thriving -- now 9 and 8 years old. They're doing great in school and are playing hockey, football, lacrosse and baseball.

"We keep going because that's what Paul would have wanted. That's what all of our lost loved ones would have wanted. We're not allowed to sit down, we're not allowed to crumble. We have to keep going in order to honor our loved ones and we honor them by living," Tuozzolo says.

And in honor of her late husband, she's putting her best foot forward by running the New York City Marathon.

"The race is going to bring out a lot of feelings inside. I'm not sure that I ever would've even dreamed about running a marathon if it wasn't for what happened to Paul," Tuozzolo says. "We'll see how I do. I know I'll cross that finish line though. That's for sure."

This is actually Tuozzolo's second time running, and she's doing it to give back and help others.

"I again am raising funds and running in honor of the Silver Shield Foundation, which is a nonprofit organization that provides scholarship funds to children who have parents that have been lost in the line of duty," Tuozzolo explains.

The Silver Shield Foundation is near and dear to Tuozzolo's heart for how they helped her family as they move forward while keeping her late husband's legacy alive.

"We are going to honor Paul by living -- that's the best gift that we could give back to Paul because the greatest gift that he gave us was being in our presence," Tuozzolo says.