(CNN) -- A former justice of the peace and his wife have been indicted on charges of capital murder in the killings of two Texas prosecutors and the wife of one, authorities announced Thursday.
The Kaufman County Grand Jury presented the indictments charging Eric Lyle Williams and his wife, Kim Lene Williams, in the deaths of Assistant District Attorney Mark Hasse, District Attorney Michael McLelland and Cynthia McLelland, the current district attorney, Erleigh Norville Wiley, said in a statement.
Hasse was killed in January on his way to work at the courthouse; McLelland and his wife were fatally shot two months later at their home near Forney.
"The murder of a public official, such as a judge a prosecutor or a law enforcement officer, is an assault on all the people of the state, because it's an attack of the rule of law," Kirby Dendy, chief of the Texas Rangers, said in April.
Kaufman County Sheriff David Byrnes previously said the killings stemmed from Eric Williams' "past legal problems with the criminal justice system of this county" -- a 2012 conviction on burglary and theft charges that led to his removal from office.
His wife has confessed to involvement in the murders and implicated her husband as the trigger man, according to court papers.
Byrnes said Eric Williams fired the fatal shots in both slayings. In Hasse's death, Kim Williams was the getaway driver; in the McLellands' killings, she was a passenger, "and Eric did the killing," he said.
"We do not believe there were any other major actors in this case," Byrnes has said.
Hasse and Michael McLelland both believed that Eric Williams blamed them for his removal from office, a sheriff's sergeant noted in Kim Williams' arrest paperwork. The prosecutors carried handguns for their protection after the Williams trial "because they believed Eric Williams to be a threat to their personal safety."
Eric Williams also was indicted for allegedly making a terroristic threat. He was arrested in April after a sheriff's affidavit accused him of using his home computer to threaten police investigating the McLellands' killings.
Jack Stoffregen, chief public defender for the Lubbock-based office for the Regional Public Defender for Capital Cases, did not immediately return a call Thursday seeking comment. His office represents Eric Williams.
CNN was unable to reach Kim Lene Williams' attorney.
Eric Williams' public defender released a statement in April saying that he "has cooperated with law enforcement and vigorously denies any and all allegations. He wishes simply to get on with his life and hopes that the perpetrators are brought to justice."