Philadelphia Police on Thursday charged a 24-year-old man with involuntary manslaughter for allegedly throwing the punch that led to the death of a fellow dog walker in a South Philly park last weekend.

Matthew Thomas Oropeza, of the 1600 block of South Sixth Street, also faces charges of simple assault, reckless endangermentand terroristic threats in Saturday’s attack on Drew Justice at Gold Star Park.

Oropeza surrendered to police Thursday afternoon, and was expected to be arraigned later in the day. As of early evening, Oropeza was still in police custody. A message left on a phone line associated with his address went unanswered.

On Tuesday, the Philadelphia Medical Examiner’s Office had ruled the death of Justice, a 38-year-old data management programmer, to be a homicide. Justice, who lived across the street from Gold Star Park, died from a “blunt impact trauma injury to the head," the office said.

Public records show that Oropeza moved into the neighborhood last summer from Delaware County, where he lived between 2013 and June 2018. Court records show two previous arrests for fighting, in Brookhaven in 2013 and in Ridley Township in 2016. In 2013, he pleaded guilty, and in 2016 his disorderly conduct charges, as well as accompanying drug misdemeanors, were dismissed after he successfully completed a diversionary program, the records show.

Witnesses told police that Justice and his fiancee, Kristi Buchholz, were walking their black Shih Tzu shortly after 9 p.m. Saturday in the park — bounded by Wharton, Marshall, Manton and Sheridan Streets between Sixth and Seventh Streets — when Justice asked Oropeza, who was walking his dog, to put a leash on his animal.

Oropeza took offense, police said, and punched Justice in the face. Justice then fell backward and hit his head on the ground. He was pronounced dead at 9:51 p.m. at Thomas Jefferson University Hospital.

In Pennsylvania, involuntary manslaughter is a first-degree misdemeanor, punishable by up to five years in prison.