(CNN) - A former Kaufman County, Texas, justice of the peace is accused of using his home computer to send a terrorist threat to police investigating the murder of the top county prosecutor and his wife, a sheriff's affidavit says.
Eric Lyle Williams, 46, was arrested and charged last week with two counts of insufficient bond and one count of making a terroristic threat, and the affidavit revealed the circumstances of the charges against him.
Authorities declined to provide details behind the charges last week, but the affidavit says that they believe Williams made the threat March 31, one day after police found the bodies of Kaufman County District Attorney Michael McLelland and his wife, Cynthia, both of whom were shot to death.
"The threat implied unless law enforcement responded to the demand of the writer, another attack would occur," said the affidavit by Richard Moosbrugger of the Kaufman County Sheriff's Office.
The threat was received "via electronic communication" by law officers investigating the two deaths, said the affidavit, which is dated April 12.
Moosbrugger says in the document that a search of Williams' home on Friday led to the discovery that he used "unique" electronic identifiers to send the threat from his personal computer.
Texas authorities are also investigating the murder of an assistant district attorney in the same county: Mark Hasse, the chief felony prosecutor, who was shot and killed on January 31. But the affidavit made no mention of that investigation and doesn't link Williams to that case.
Williams is being held in lieu of $3 million bail -- $1 million for each charge he faces -- according to the sheriff's office.
Williams has a history with law enforcement authorities, including the Kaufman County district attorney's office.
Last year, he was sentenced to two years of probation after a conviction for burglary and theft by a public servant. Hasse prosecuted Williams' case.
Hours after the McLellands' bodies were found, authorities met with Williams at a local Denny's restaurant, Williams' attorney, David Sergi, said this month.
Investigators took swabs of Williams' hands to test him for gunshot residue, according to the lawyer. Results were not made public by officials, but Sergi said the tests came back negative.
On Friday, Sergi released a statement saying that Williams "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."
Williams told North Texas TV station KXAS this month that he understands why authorities wanted to meet with him.
"If I was in their shoes, I would want to talk to me," he said. "In the investigators' minds, they want to check with me to do their process of elimination."
Williams said he has no ill will toward prosecutors -- they were "doing their jobs," he said -- and has cooperated with law enforcement.
"I certainly wish them the best in bringing justice to this incredibly egregious act," he said.