The TBI said Sgt. Daniel Baker responded to a report of a suspicious vehicle around 7 a.m. After not hearing from the deputy for a period of time, the officer's patrol car was tracked by GPS.
Baker was found dead in the patrol car about two miles away from the initial call in a wooded area.
The TBI said video evidence led to the identification of suspect Steven Wiggins. Agents developed information that Erika Castro-Miles participated in the officer's death.
She is an acquaintance of Wiggins and was charged with one count of first-degree murder. Castro-Miles was the woman detained earlier on Wednesday as part of the investigation.
Baker's mother gave a statement to FOX 17 News, saying he was a husband, father, and former Marine. He leaves behind a wife and young daughter.