In April, Rust was indicted on two counts of felony abuse of official capacity, one felony count of theft by a public servant and 10 counts of operating a security company without a license following an investigation by Te-xas Rangers and the Department of Public Safety.
Each state jail felony count carries 180 days to two years in jail and a $10,000 fine.
The third-degree felony theft for using taxpayer dollars to illegally run the security business for benefit carries between two years and 10 years in prison and up to a $10,000 fine.
Rust continues to deny any involvement in a security business but would not elaborate on the possible trial because of a gag order.
On May 29, Rust finished last in a four-candidate primary race. Jim Blackmon, a Bullard police officer, eventually won the July 31 runoff and is expected to be sworn in on Jan. 1.
On Monday, Rust said he will resign as constable because he is considering a position with another area law enforcement office and acceptance of the post would be a conflict of interest. Rust said he would not “throw away” his law enforcement training and experience. He will continue his police equipment business Emergency Response Technologies.
Commissioner Cary Nix said he could not speak for the court, but the “logical” action would be to appoint Blackmon.
Blackmon said he had not been officially contacted by the court regarding taking office early, but said he would be available if needed.
Rust, who was elected in 2008, said he hopes his replacement does well. His office has a productive history. Despite receiving the lowest funding from county commissioners since his tenure began, Rust's office has served the second-highest number of civil process papers each year, behind a geographically smaller Precinct 1.
“I'm just glad to be out of Smith County politics,” he said.