Ammar Haroun, 23, is accused of killing Carlos Hamilton, 19, last summer.
Court documents show police linked Haroun to the shooting using evidence used in other cases, DNA.
Hamilton was found dead in his car outside the Walgreens at Coliseum and State just after midnight July 21, 2018.
Court documents say surveillance video from the pharmacy and the Mikes Carwash across the street show Hamilton went to the store just before 10 p-m.
Video shows someone got in the car with Hamilton. Shortly afterwards, that person got out of Hamilton's and into another one that sped down State.
Court records show Hamilton and Haroun ... under the screen name G-SMOOTH, were friends on Snap Chat and chatted just before the shooting.
Documents state Hamilton's mom told detectives he also shot Haroun in the car.
That's when detectives searched the car for evidence including DNA.
Lab reports completed last month say the DNA on the door handle and center console matched Haroun's.
He was taken into custody Friday evening.
Haroun is locked up without bond.