Rob, Michele Reiner son Nick left key evidence at hotel after murders

Rob and Michele Reiner’s son Nick reportedly left hotel staff shocked with a blood-stained room.

Nick checked into the Pierside Santa Monica hotel in Santa Monica at 4 AM Sunday using his own credit card. The room was booked for one day.

According to hotel staff, he appeared "tweaked out" during the check in but there was no blood on him anywhere.

Nick’s check in came hours after he reportedly had a loud argument with his dad at Conan O'Brien's Christmas party, according to TMZ. 

According to sources, Nick was "acting crazy," behaving "creepily" and "freaking everyone out" at Conan’s party.

Los Angeles Police Department Robbery-Homicide Division detectives went to the hotel to look for evidence in his room and interview hotel staff.

Later in the day, housekeeping went to clean the room and found the shower "full of blood". The bed sheet was also stained with blood and the windows were covered with the bed sheets.

Nick was eventually found around 20 miles away in Exposition Park, near Downtown LA and arrested and charged for the murders.

The screenwriter has battled with addiction for years and been in an out of rehabs.

Other sources close to the family told Us Weekly that Nick had been hostile toward his parents and siblings, Romy, 28, and brother Jake, for years.

"A lot of his anger was directed at his parents for many, many years," the insider explained. "They did everything a parent could possibly do to help him. Even in his younger years, they really tried to get him help. And then it became a cycle of seeking treatment for him, kicking him out, or him leaving the house, him moving back in."

"This went on for years," claimed the mole.

Nick is now in DTLA’s Parker Center Jail before being transferred to Twin Towers Correctional Facility. He is being held without bail.