Zaki Harrell was arrested on Thursday and charged with murder.
Just last week, Christopher Battle turned himself into police after eight months on the run.
RELATED: Video shows multiple people opening fire in Grays Ferry mass shooting that left 3 people dead
The gunfire erupted during a block party along the 1500 block of South Etting Street just before 1 a.m. on July 7, 2025.
Three people were killed, and nine others were injured.