Brandon Ruffin, 22, who allegedly fired the shot that killed Tynirah Borum, was arrested late Monday, police said. Another man, Douglas Woods, 22, had already been arrested.
Three adults were wounded in the confrontation Friday evening, Homicide Capt. James Clark said. A 24-year-old man was in critical condition with a head wound while a woman, 28, and another man, 21, were in stable condition.
Borum, who lived nearby, was on a porch in the Grays Ferry neighborhood having her hair braided when she was shot. Investigators said that Ruffin and Woods, who were on bicycles, approached the porch and got into an argument with the 24-year-old.
Ruffin allegedly pulled out a gun and opened fire.
Clark said police were familiar with both Ruffin and Woods. Both had served short sentences on gun possession charges, with Ruffin paroled only a month ago.