Detectives also issued an arrest warrant for a third suspect, Keith Devine, 26.
Stelly, a mother of four, died of a shot to the head.
Three alleged killers. One killing shot.
Sgt. Ronald McClane, a detective on the case, said that the ballistic analysis of the slug that killed Stelly was incomplete, and that investigators had not identified the triggerman.
But the principle behind multiple arrests for a single murder is simple, he said: Fire a weapon while committing a felony and face maximum charges if that action contributes to a death.
"The city, the department, the public in general is fed up" with homicides, McClane said. "If you're out there shooting, the D.A.'s Office will come down on you. I think that's in everybody's interest."
While some anti-violence activists applaud such action, Stephanie Dixon, an organizer of a march today to commemorate Stelly, said that some members of her family were upset about the arrest.
"It's not right. They had nothing to do with it. They were dodging bullets just like everybody else. . . . Michael [Stelly] was there just trying to save his sister," Dixon said last night.
The victim's four children, Rashiek, 9, Curtise, 7, Jaylah, 3, and Naj, just a few months old, are being cared for by an aunt, Shelley Myric, Dixon said.
The march, scheduled to step off at 5 p.m. today from 58th Street and Willows Avenue, is "for Jovonne Stelly, but it's also for all the other people dying in this city all over. There's too much bloodshed," Dixon said.
A witness told a reporter Monday that the gun battle, in which up to 40 shots were fired, began when an unspecified number of gunmen emerged from a house and started shooting.
Capt. Michael Costello, commander of the Homicide Unit, said tensions between the two groups involved in the bloody melee, in which four people were wounded, had been building for two weeks and apparently stemmed from a robbery and a subsequent shooting in which no one was hit.
He said that despite Stelly's relationship to the men in custody in her slaying, there was no indication that she was involved in the dispute. She was killed, he said, "trying to remove her children from the line of fire."
Devine's relationship to High and Stelly was not spelled out by police. All three were known to police from previous encounters, officials said.
Costello said at least four guns were fired during the gun battle and police were hunting for others who fired shots.
The feuding factions had engaged in a number of physical confrontations in the last week, including Sunday morning, and from 15 to 20 people gathered on Pentridge Street Sunday afternoon in apparent anticipation of a fistfight, Costello said.
Besides the two groups, children and adults enjoying the good weather also were on the street, he said.
"But at least four to five people brought guns to this fistfight and they didn't think twice about discharging them," Costello said. "It's just insane."
He said that once again, investigators were hindered by the reluctance of witnesses to cooperate.
"I would describe the cooperation we got on this investigation as sketchy at best," he said.
Contact staff writer Joseph Gambardello at 215-854-2153 or firstname.lastname@example.org.
Inquirer staff writer Jeff Shields contributed to this article.