(AP)  The husband of death-row inmate Darlie Routier is divorcing his wife.

The 40-year-old woman was sentenced to death for killing her middle son, 5-year-old Damon, in 1996.

Darin Routier told The Associated Press on Friday that he still believes in his wife's innocence and that the divorce was a mutual decision that was "very difficult.''

His attorney filed the papers Wednesday in Lubbock, where he lives with the couple's youngest son, Drake, who is 15.

Darlie Routier contends an unidentified intruder killed her sons and stabbed her in the family home in Rowlett, a suburb of Dallas. Six-year-old Darin also was killed.

Her conviction is being appealed in federal courts, Darin Routier said. She is among 10 women on death row in a Gatesville, about 316 miles southeast of Lubbock.