Bill Stevenson, the ex-husband of former First Lady Jill Biden, is in custody in Delaware after his wife was found dead inside their Wilmington home on Sunday night, police have said.

New Castle County Police said in a press release that officers were called to the home in the Oak Hill section of the city after receiving a report about a “domestic dispute” at 11:16 pm.

The statement says that officers found Linda Stevenson unresponsive in the living room. Despite life-saving measures being taken, the 64-year-old was pronounced dead. An autopsy is scheduled to determine the cause of death.

Jill Biden married Stevenson in 1970 while she was still a college student. The pair divorced in 1975, two years before she married former President Joe Biden in 1977.

TMZ reports that Stevenson called authorities.