A petty social media beef between warring groups of young men escalated to an open-air gun battle earlier this month on a Norristown street and took the life of a man sitting on his sister’s porch, prosecutors said Thursday.

Barry Fields, 51, was struck once in the head, the only casualty in a Sept. 18 shootout that took place on the street his family has lived on for decades, his sister Jodi said.

Now, as prosecutors announce they have arrested two of the men they say are responsible, Jodi Fields is urging the others involved — or those who know who they are — to come forward.

“I’m not seeking to get revenge or anything, I just want justice for my brother,” she said. “If you see something, say something. Because I would do it for them if they had a tragedy like I did.”

Brandon Darden, 25, and Joshua Agudio Jr., 20, both of Norristown, have been charged with first-degree murder and related offenses in the fatal shooting on Astor Street. An arrest warrant on similar charges has been issued for Edwin Islas-Cruz, 23, also of Norristown, according to Montgomery County District Attorney Kevin Steele. A fourth, currently unidentified gunman is also being sought by detectives.

It’s unclear which of the men fired the shot that killed Fields, who underwent double transplant surgery for his kidneys and pancreas in 2017 and had fought long to pull through and enjoy a new lease on life.

Darden and Agudio were arrested Tuesday and Thursday, respectively, and remained in custody, denied bail due to the nature of their charges. There was no indication Agudio had hired an attorney. Darden’s attorney, Francis Walsh, said his client denies any involvement in the shooting, but declined to comment further.

In a statement Thursday, Steele vowed to find and prosecute all of the members of the two groups who traded gunfire that day.

“Mr. Fields was murdered while sitting on the steps of his residence on a sunny Saturday afternoon, when these defendants decided to take out their disagreement with each other using guns, and they subsequently killed Mr. Fields,” the DA said. “There is no place for this kind of dangerous Wild West shootout in Norristown or anywhere in Montgomery County.”

Nearly 40 bullets were fired by the groups, according to the affidavit of probable cause filed in Darden’s and Agudio’s arrests. One of the guns used in the firefight that killed Fields was also wielded by Islas-Cruz in a separate shooting two days earlier in Norristown, prosecutors said. He is also being sought on attempted murder charges for that incident.

Surveillance footage and interviews with witnesses led police to Darden and Agudio, according to the complaint. None of the men charged or being sought in this case is legally eligible to possess guns due to previous convictions, the affidavit said.

The Sept. 18 incident began just before 5:30 p.m., when Darden and Agudio were hanging out with a group of other men outside Darden’s home, a few houses down from Jodi Fields’, the affidavit said. As the men gathered outside, authorities said, a Toyota Camry pulled toward them, and Islas-Cruz and another man got out of the car and opened fire. Darden and Agudio returned fire, the affidavit said, and the two other gunmen got back into the Camry and sped away.

Fields’ sister said she and her daughter rushed inside when the first shots rang out. Otherwise, she said, they, too, likely would have been hit.

Of her brother, she said: “He was just the sweetest person you could ever know. He didn’t have any issues with anyone. It should’ve never happened.”