The “Ghost Adventures” episode featuring Weezer bassist Scott Shriner’s ex-wife, Jillian, is about to air … and TMZ’s got the chilling first look, giving a pretty unsettling peek into her headspace before that wild run-in with cops earlier this year.

Have a look — Zak Bagans says things took a seriously dark turn after Jillian gifted him serial killer Samuel Little‘s ashes, along with hand-drawn portraits of his victims that he’d left her in his will after she once wrote a book about him.

Zak says Samuel’s remains were placed inside his Vegas Haunted Museum, alongside Charles Manson’s, and it wasn’t long before strange activity started popping off … triggering a pretty intense reaction from Jillian.

Jillian says those ashes were literally in her home, and every time she walked into the room, she felt herself folding, sinking deeper into depression.

Remember … production sources told TMZ Jillian filmed the episode in November last year … and just months later, in April, she allegedly fired a gun at officers searching for a suspect near her Los Angeles home in an unrelated incident.

Jillian was arrested on suspicion of attempted murder of a peace officer, but prosecutors later downgraded the charges to assault and negligent discharge of a firearm. She avoided jail time — with a judge granting her diversion due to mental health issues.

We broke the story that Jillian filed to divorce Scott earlier this month after being married for 20 years.

Claudio Manuel Neves Valente, the man accused of shooting up Brown University Saturday and then gunning down MIT professor Nuno F.G. Loureiro at his home Monday, used “sophisticated” tactics to hide his tracks as he attempted to conceal his horrid actions.

US Attorney for the District of Massachusetts Leah Foley laid it all out in a press conference Thursday night, revealing Neves Valente likely used an untraceable phone and avoided using credit cards tied to his name. He is also said to have switched the Florida license plates of his rental Nissan to unregistered license plates from Maine within 24 hours of the Brown shooting, and before he slayed Loureiro.

As for his connection to the MIT nuclear physicist, prosecutors say the pair attended the same academic program in Portugal between 1995 and 2000. Loureiro was found shot at his Brookline, Massachusetts home Monday and died Tuesday. The specific motive for murdering Loureiro remains unclear.

Nancy Grace says the double homicides of Rob Reiner and Michele Singer Reiner are a textbook example of a case that calls for the death penalty … and that could be bad news for alleged murderer Nick Reiner.

Nancy tells TMZ … this case is the classic example of when capital punishment should be applied, but that doesn’t mean it’s going to happen.

Los Angeles District Attorney Nathan Hochman mentioned the death penalty in a recent press conference, so it’s being talked about among prosecutors … but as Nancy explains, a final decision on capital punishment goes way beyond the D.A. office.

Nick is charged with murdering his parents at their Brentwood home … and he’s being held without bail and is on suicide watch as he awaits his January arraignment. He’s hired famed defense attorney Alan Jackson.