Earlier Sunday evening, a person was seen turning themselves in to officers at a Chicago police station at Harrison and Kedzie.
Neuman was working in his yard in West Garfield Park earlier this week when he was shot and killed.
The arrest comes after Neuman's community gathered together earlier in the day on Sunday for a powerful prayer march and vigil in honor of his life.
Vigil held for retired CPD officer fatally shot outside West Side home
"He was a great man, just a great man," Deacon Albert Henderson said. "He was a veteran. He was a Chicago police officer. He was a reverend at our church."
Members of Neuman's church came together with city and state leaders, rallying at St. Michael Missionary Baptist Church and marching to the place he was shot on the 4300 block of West Monroe Street.
ABC7 was told the deadly shooting may have happened during a robbery attempt.
"I know as a community we can come together to not just grieve, but we can come together to restore," Chicago Mayor Brandon Johnson said.
Those gathered there Sunday looked for a path to healing while honoring the legacy Neuman leaves behind.
"Looking around here right now, his loss was actually a blessing, because when you looking at everybody coming together right now, this is the start of something," Chicago Police Department Superintendent Larry Snelling said. "He was always willing to put his life on the line to do what is right and to keep people safe."
Neuman was remembered as a man who did things with meaning and who brought meaning to his West Side community.
"He served the city and served his country," co-worker Thelma Kinnard said. "He's been serving people, even in the ministry."
Chicago police released video on Saturday of two suspects wanted in connection with the shooting death. The video shows one male wearing a dark hoodie and Jordan shoes. Police said the suspects appear to be between 16 and 21 years old.
"Everything I needed, whatever I needed. I could call him for anything. He'll be there," friend Shonda Johnson said. "He was everything to everybody in this community. He was the father to figure kids that father wasn't in their life. He was a father figure to all the kids in the neighborhood. He watched over everybody's kids."
There are a total of $75,000 dollars in rewards being offered for any information that could lead to an arrest and conviction.
The rewards are being offered by the Chicago Police Memorial Foundation, ATF Chicago and FBI Chicago.
Anonymous tips can be submitted at CPDTip.com or by calling crime stoppers at 1-800-535-STOP.
"As long as God give me breath... I am always going to remember his name: Larry Neuman," Shonda Johnson said.
No further details about the person in custody were immediately available as police continue to investigate.
Neuman's funeral services have also been announced.
Visitation for Neuman will be from 3 to 8 p.m. Friday at St. Michael Missionary Baptist Church, 4106 W. Monroe St., where Neuman was a member for 30 years as well as a pastor. Funeral services will be held at 10 a.m. Saturday at St. Michael.
Sun-Times Media contributed to this report.