Jill Biden's Ex-Husband's Wife Dies After Cops Called for Domestic Dispute

Jill Biden's first husband, Bill Stevenson, is now a widower ... because Bill's wife was pronounced dead at their Delaware home after cops were called for a domestic dispute, and found her unresponsive ... TMZ has learned.

New Castle County Police tell TMZ ... officers responded to a reported domestic dispute at a home in Oak Hill around 11:15 Sunday night and found Linda Stevenson unresponsive in the living room.

Cops say officers immediately administered life-saving measures, but Linda was ultimately pronounced dead.

Now, get this ... New Castle County Police tell us detectives from the Division's Criminal Investigations Unit are handling the death investigation.

No charges have been filed in the case. Linda's body has been turned over to the Delaware Division of Forensic Science for an autopsy to determine the cause and manner of death. Dispatch audio, obtained by TMZ, from the incident mentions cardiac arrest.

Jill married Bill in February 1970, when he was 23 and she was a student at the University of Delaware. Two years later, Bill opened a hugely popular college bar near the UD campus, The Stone Balloon ... in 1974 Jill and Bill separated and went through a nasty divorce where Jill tried, and failed, to get half ownership of the bar.

Joe Biden married Jill a couple years later in June 1977, when he was a senator from Delaware.

Linda was 64.