Weeks later, in a recorded interview, Jeremy told a psychiatrist what was going through his mind. "My mom, I thought she was out to get me," he said. "Like sometimes she'd be totally normal and then she'd have that face again."
Dr. Brian Joseph was one of at least eight psychiatrists who concluded that Jeremy suffered from schizophrenia.
Asked to explain what schizophrenia is, Dr. Joseph says "Schizophrenia is a brain disease where one nerve cell doesn't seem to talk properly to another nerve cell. You begin to have psychological symptoms such as feeling people are out to get you when they're not, hearing voices when no one is there."
For Dr. Joseph and John Nuchereno, the attorney who represented Jeremy in his criminal proceeding, the real tragedy is that Jeremy never got proper psychiatric treatment.
"His parents knew that he was extremely ill and experiencing hallucinations," Nuchereno says.
Asked if they called a psychiatrist, Nuchereno says, "No."
Elli and Don Perkins sincerely wanted to help their beloved son, Jeremy. But the Perkinses were Scientologists. Some pro-Scientology materials declare that psychiatrists are not only useless, but evil - their medications nothing but poisons.
Most of us know about Scientology from the celebrities in the church, like John Travolta and Tom Cruise. Those Hollywood stars are the most visible members of a church which today claims 10 million members worldwide.
Scientology says its mission is spiritual betterment, philanthropy, and advancing human rights. As for the Perkins case, the church says that Elli's murder had nothing to do with her faith.
But sources close to the case - and previously sealed court documents - tell a much different story.
Elli, an artist, had been raised Jewish; Don, a contractor, had a Christian background.
One of Elli's best friends, Dawn, says Elli was searching for spiritual answers. "Sort of knowing that she had a purpose but not knowing what it was," she explains.
We're not certain exactly how Elli was introduced to Scientology, but today the church often recruits new members with a free personality test or stress test, as 48 Hours documented with hidden cameras at a booth in New York City.
Church members use a device, called an E-Meter, to determine what's troubling you. The E-Meter measures the body's resistance to electrical current. The church is required by law to affix a label to each machine stating that it serves no medical purpose.
"They'll say, 'Oh, look. The E-Meter moved when I asked you this. This means you're stressed. Come on in and we'll help you out,'" says Rich Dunning, who knows about the E-Meter. He's a former deputy director of the Buffalo Church of Scientology, where he met the Perkins family.
Dunning says Scientologists believe the device is real, but that he does not.
After our stress test, we got a sales pitch for a book, "Dianetics." The book, published in 1950, was written by Scientology's founder, a prolific science fiction writer named L. Ron Hubbard.
"The aim and goal of Scientology is to take an individual and put them in a position where they can confront their own problems, and solve their own problems," Hubbard explained.