One group honoring him is the Swagga House Run Club.
Their goal is to engage Black and Brown youth through running in some of the city's neighborhoods most impacted by gun violence.
"You hear when people pass they were the best of the best, but truly... Chris truly was," said Josh Perez.
Community mourns fallen Temple University police officer
Josh Perez once worked with Officer Fitzgerald at the Philadelphia Sheriff's office, and is one of the co-founders of Swagga House Run Club.
The group, which Perez describes as more like a family, meets up once a month for Sunday runs through the city.
He says their mission is to encourage at-risk teens in some of the city's hardest-hit areas, and help them channel their energy through running - and even join their club.
The group already had a scheduled run on the books over the weekend, but members took time to honor Fitzgerald, whose absence was his presence.
"I was with his wife when the doctors gave her the news, and one of the first things she said to me was, 'Chris and I were going to run with you guys tomorrow morning,'" he said.
"We knew we had to have it, and with heavy hearts we ran, and we carried him in our spirit," he continued.
A suspect has been arrested for the murder. Miles Pfeffer, 18, was arrested Sunday morning in Bucks County and is being held without bail in a Philadelphia prison.
Who is Miles Pfeffer, teen charged with killing Temple officer?