Police say Simmons was in a car driven by Kareem Bundy, also of Philadelphia. The car was pulled over for speeding around 2:00 a.m. in the town of Whitehall.
Police ran the identification of both men and learned that Simmons was wanted for murder in Barnes' death. Bundy was wanted on an outstanding parole violation.
Both men are jailed in New York awaiting extradition to Pennsylvania.
On the afternoon of July 25, Barnes was doing carpentry work at the Raymond Rosen Manor in North Philadelphia.
He went to get tools out of his truck when he was shot in the head at point blank range.
Barnes succumbed to his injuries on August 5th.
Barnes had been working for PHA in the neighborhood every other weekend for about 6 months.
A reward of $53,000 was being offered for information leading to an arrest.