Billy Joe Colburn involved three other people in his plan, according to a police detective.
One of those -- William Ballinger, 19, of Old Columbia Road -- was arrested Friday by Shelbyville police, Detective Sgt. Brian Crews said.
"Our investigation has revealed that Billy Joe Colburn set out to find a Hispanic male to rob," Crews said. "To facilitate the robbery Billy Joe Colburn solicited the help of William Ballinger and two females who were to pose as girls willing to prostitute. The females were willing participants in the plot."
McKenzie Drew Hickson, who Crews said has just turned 18, of Russell Street and a girl who just turned 17 have been arrested, police said.
"They drove around town until they found a man pumping gas at the North Main Kangaroo," Crews said. "At the Kangaroo the females approached him and asked him if he wanted to hang out later and party. The girls exchanged numbers with him and then called him later.
"The conversations led to the girls asking him if he would be interested in having sex in exchange for money. They also invited him to bring a friend."
The man and his friend met the girls at Bedford County Agricultural Center, where they were led to an abandoned house on Midland Road.
"Once the victims exited their car they were assaulted and robbed," Crews said. "The victims fled on foot all the way to Walmart, leaving their car behind."
The in-dash stereo system and an iPod were stolen from the car, police said.
"Fortunately for us, while the victims were inside Walmart waiting on a ride back to their car three of the suspects entered and were observed by the victims," Crews said. "We were able to identify three of the suspects from the Walmart video surveillance."