DALLAS (CBSDFW.COM) – Police have arrested two people in connection to an aggravated robbery at 4700 Fellows Lane that ended in a 12-year-old’s death.

Kendrion Sullemon, 17, admitted to police that he fired into a car, hitting the girl in the head and grazing a 15-year-old who had agreed to sell a phone via the LetGo app. Two other teenagers in the victim’s car were not injured.

The shooting happened after the surviving victim tried to drive off after he felt uneasy when the Sullemon, and another suspect, Rodrick Spearman, 20, changed meeting places.

Spearman was arrested on June 19 and confessed to his part in the offense, according to police.

For people who want to buy and sell their goods safely, the Dallas Police Department and OfferUp have set up the city’s first Exchange Zone. It’s designed to create a safer space for buyers and sellers during online transactions. The location is well-lit and monitored.