Authorities say a Delaware man who was once married to former first lady Jill Biden remains jailed on first-degree murder charges in the death of his wife. William Stevenson, 77, was charged in a grand jury indictment with killing Linda Stevenson, 64, who was found unresponsive in their Wilmington home on Dec. 28 after police responded to a reported domestic dispute. Stevenson has failed to post $500,000 bail and remains in custody. Investigators have not disclosed a motive or identified a defense attorney. Jill Biden declined to comment through a spokesperson.