Darrell Anderson, Christopher Ingram, and Dontavius Wilson are charged with shooting Jack Camp more than three year and a half years ago.
Prosecutors say Camp was shot when he interrupted a drug deal at an East Albany apartment complex where he worked as a security officer.
Two former Dougherty County Jail inmates testified they heard the suspects talking about the crime in jail after their arrest.
A former Albany Police Investigator was the last prosecution witness.
The trial is expected to go to the jury Friday.