Debbie Constantino and her estranged husband Mark, paranormal investigators best known for their appearances on Ghost Adventures, were found dead in their adult daughter’s apartment in Sparks, Nevada on Tuesday.

According to a report from Fox 8 in Nevada, police began “an investigation around 6:30 a.m. when a woman arrived home and found her male roommate dead. Officers then learned that the woman’s other roommate, Debbie Constantino, was also missing.”

Investigators soon tracked Debbie Constantino’s cell phone to the adult daughter’s apartment. When officers knocked on the door, Mark Constantino told them to give him 15 minutes to “gather his thoughts” or he would kill Debbie.

Paranormal investigators Mark and Debbie Constantino found dead in Reno: http://t.co/NDgmLXPVge (Photo: RGJ file) pic.twitter.com/Y63HuHT6C2

— USA TODAY (@USATODAY) September 24, 2015

Several shots were fired inside the house, and officers eventually used explosives to blow the door down. When they entered the home, they found both Mark and Debbie Constantino dead inside.

A report from KRNV-TV says Mark and Debbie Constantino were estranged, and that he was arrested last month on kidnapping charges, as well as domestic battery by strangulation, and domestic battery–all involving his wife.

While it certainly sounds like this is a murder-suicide, it’s uncertain if the other person killed at the place Debbie Constantino was living was involved with the couple, or simply someone Mark Constantino killed in order to get Debbie out of that residence. All police have said is that the two incidents are “directly related.”

Did you ever watch Mark and Debbie Constantino on Travel Channel’s Ghost Adventures?

It’s very sad to learn their lives have come to such a tragic end.