THE WIFE OF A FERTILITY DOCTOR IS FOUND DEAD - DID HER DOGS PLAY A ROLE OR WAS THE SCENE STAGED TO COVER A MURDER?

On Nov. 13, 2016, Dr. Eric Scott Sills, a renowned California fertility doctor, called 911 and reported finding his wife and business partner unresponsive at the bottom of the stairs. An initial investigation revealed some evidence that was consistent with an accidental fall. But other evidence pointed to something more sinister. What role, if any, did the family dogs play? Correspondent Tracy Smith reports in 48 HOURS: "The Puzzling Death of Susann Sills," to be broadcast Saturday, May 18 (10:00 PM, ET/PT) on the CBS Television Network, and streaming on Paramount+.

Dr. Sills said on the 911 call that it looked like his wife tripped and fell on the staircase after suffering from a migraine all weekend. Minutes later, 45-year-old Susann Sills was declared dead at the scene. Orange County Sheriff's Homicide detectives Eric Hatch and Dave Holloway were called to conduct a death investigation.

"The deputy coroner, during her preliminary body exam of Susann, the injuries weren't consistent with somebody falling down the stairs," Det. Hatch said.

"Her neck had a pretty pronounced ligature mark," Det. Holloway added.

The Sills' daughter, Mary Katherine, told detectives her mother had a scarf around her neck when she was discovered that morning.

Smith asked Det. Holloway if it was possible Susann Sills could have fallen down the stairs and been choked by her scarf. Holloway said her scarf could have gotten caught on the banister, but added there was no evidence pointing that way.

The investigation took months, but in November 2017, Susann Sills' cause of death was cited as ligature strangulation and the manner as homicide. Dr. Scott Sills was then the prime suspect.

Defense attorney Jack Earley said there are two other possible culprits, the family dogs. He suggested Susann Sills fell on the stairs and the family dogs tugged on the scarf wrapped around her neck.

"Do you honestly think that the dogs pulled hard enough to strangle her to death?" Smith asked Earley.

"No, no, I didn't," Earley said. "That was not the main theory that the dogs actually strangled her to death."

Instead, Earley focused on another injury identified in Susann Sills' autopsy, a fractured vertebra in her neck. He says that injury is consistent with a fall, and that it would have left her incapacitated.

"Their breathing is compromised. If they're then choked, it doesn't take much to kill 'em," Earley said.

What happened in the Sills' house? 48 HOURS and Smith report on the investigation and the trial in "The Puzzling Death of Susann Sills."

Judy Tygard is the executive producer of 48 HOURS, which is broadcast Saturdays at 10:00 PM, ET/PT on CBS, and streams anytime on Paramount+. You can also watch 48 HOURS on the CBS News Streaming Network Wednesdays at 8:00 PM, ET. 48 HOURS is also available on CBSNews.com, Fave TV, Pop TV, Pluto US, Pluto UK, Pluto Nordics, Pluto Canada and Pluto South Africa. Download the CBS News app on your phone or connected TV. Follow 48 HOURS on X, Facebook and Instagram. Listen to podcasts at CBS Audio.