Missing tapes could solve mystery behind one of America’s most notorious serial killers

Missing video tapes could prove crucial in solving the mystery behind one of America's most notorious killers.

Back in the early 1990s, Herb Baumeister is believed to have killed 25 young men, after meeting victims at gay bars in Indianapolis before taking them back to his home and killing them.

Authorities first began to recover human bones from the 18-acre Fox Hollow Farm in Westfield in 1996, after the successful businessman and married father-of-three moved into the property with his family in 1988.

In 1994, Baumeister's 15-year-old son discovered a human skull in the woods behind the home at around the same time police started searching for a serial killer targeting gay men.

Baumeister's wife, Julie, confronted her husband about the find and he initially claimed it must have been left over from his father’s physician’s practice, detectives said.

The home where the serial killer is suspected to have commented the murders (ABC)

After Julie filed for divorce in 1996, she had police search the property and they uncovered a skull, teeth and other bone fragments.

The search eventually led to the discovery of more than 10,000 'burnt and crushed' bone fragments or pieces belonging to victims, which led to officials putting out an arrest warrant for Baumeister.

But he fled to Ontario, Canada, and took his own life before he could be charged with any crime.

Decades on, the serial killer's methods still remain a mystery, though a series of tapes could provide officials with some indication.

Baumeister is believed to have filmed before and during the killings, which was captured by a secret hidden camera in the basement.

When he fled to Canada, the serial killer is believed to have taken the evidence, with Julie confirming a large tape collection had been taken from their home.

Herb Baumeister died before he could be charged (WTHR)

Mark Goodyear, who is thought to be the sole survivor of Baumeister's, told ABC News Studios how the serial killer forced him to watch some of these horrific videos.

He said: "It was bad, bad. You couldn't make it out. It was like having a camera right up against something. You’re not going to be able to tell what’s going on but the minute you got a flash of what was going on, it made you scream."

Speaking of his interactions with the serial killer, Goodyear claimed Baumeister 'put his hands inside my mouth' after he screamed upon watching the videos.

"He grabbed my tongue, he held my tongue," Goodyear said.

"For somebody to put themselves inside your mouth and grab your tongue. You’re scared to death, you're just scared, you’re terrified... I begged to die. Begged to die."