Elbert Edward Brooks, 48, of New Albany, was arrested late Wednesday. He told Indiana State Police Detective Shane Staggs that he went with the other suspects to the rural mobile home of Nicholas Fields, 56, of Paoli, "thinking they were going to get methamphetamine," according to a probable cause affidavit filed in Orange Circuit Court in Paoli.
A second suspect, James L. Davidson, 36, was arrested on Friday in his brother's home near Marengo. Police said he was arrested without incident.
Brooks said he was waiting in a vehicle when he heard a series of gunshots. Then, Brooks said, Davidson and a third suspect, John Carpenter, 35, both of Marengo, returned to the vehicle and "they stated that it had went wrong." Brooks said they returned to Marengo, where he was given money and some methamphetamine, the document said.
Brooks was being held Thursday on $1 million bond while police continued searching for Carpenter. Online court records showed Brooks did not yet have an attorney.
All three face two counts of murder, one count of attempted murder and one count of robbery, and Carpenter and Davidson also face charges of being habitual criminals.
Carpenter and Davidson are both considered armed and dangerous.
"We do not believe they're together," State Police Sgt. Philip Hensley said.
Police have said that Carpenter was last seen driving a pickup truck.
On Friday, police announced they were also seeking Anette D. Davidson, 54, the wife of James Davidson, for allegedly aiding her husband in hiding from authorities.
Fields died Monday and Corey Michael Harris, 25, died Tuesday at a Louisville, Kentucky, hospital. A third man, Daniel Smitson, 29, is recovering from a gunshot wound to the mouth. Each victim is from Paoli, located about 45 miles northwest of Louisville.
Smitson told Staggs that Carpenter, after arriving at Fields' home, ordered him and Fields to get on the floor and shot both of them in the head, the affidavit said. Harris was shot while crawling toward a street.
Guns also were taken at Fields' home and later thrown into a river, it said.
Hensley declined to discuss the motive for the shootings but added: "We do believe this was a targeted incident. This wasn't random."