Police reports suggest a shooting victim and his girlfriend were being followed about two months before he was fatally shot in North Knox County last week.

On Oct. 10, a shooting killed Cameron Smith, 19, and seriously hurt Lucas Halliburton, 20. Investigators are still looking for the suspects, who they said drove a black Ford Mustang.

Investigators also have not released a motive.

According to a report filed Aug. 24, a Knox County Sheriff’s Office deputy responded to a call from Smith, who said he was getting threatening messages from a person he said he didn’t know after responding to an Instagram post. Smith also told the deputy in the report that a 2007 silver Ford Mustang “with loud exhaust” had driven past his home several times.

MORE: Friends, family hold memorial for Cameron Smith

According to a report filed Aug. 23, a Knoxville Police officer responded to a call from Carly Yarnell, who told the officer a man approached her at a gas station, saying he followed her from her home and wanted to know where Smith was. Also in the report, Yarnell told the officer she earlier got a message from a person she said she didn’t know, and when she met up with the person, they claimed Smith was “talking bad” about person’s father.

KCSO would not confirm if these reports were related to the shooting investigation.