The charges against Eric Williams, 46, in the deaths of Kaufman County District Attorney Mike McLelland, 63, his wife Cynthia, 65, and Assistant District Attorney Mark Hasse, 57, are expected to be filed as early as Tuesday, law enforcement authorities in Kaufman, Texas, told The Dallas Morning News.
McLelland and his wife were found shot to death at their home in a rural subdivision some 30 miles southeast of Dallas March 30. In January, Hasse was gunned down in a parking lot near the county courthouse.
Williams was in custody at the Kaufman County Jail on a $3 million bond after being taken in shortly after 12:30 a.m. Saturday, officials said.
Williams attorney David Sergi said his client "vigorously asserts his innocence and denies any involvement" in the killings.
McLelland and Hasse successfully prosecuted Williams last year on charges of stealing computer equipment from a county building.
He was convicted of burglary and theft charges, sentenced to two years' probation and fined $2,500.
A state judicial commission removed Williams from office and a disciplinary board suspended his law license.
Williams also faces separate theft charges from his time as law librarian at the Kaufman County Courthouse before he became justice of the peace.
During his trial, Williams said McLelland and Hasse didn't like him, KTVK, Dallas, reported.