Defense attorneys are hoping to discredit the confession that is expected to be a key piece of evidence in Jacob Sullivan’s trial for the rape and murder of Grace Packer, his girlfriend’s adopted daughter.

Grace’s mother Sara Packer is also facing murder charges, and was implicated in Sullivan’s confession.

The Morning Call reports that defense attorneys are seeking to suppress statements Sullivan made to police in January of last year, admitting to raping and murdering Grace in a rural Pennsylvania home in July 2016.

The attorneys are reportedly arguing that Sullivan’s statements should not be admitted because he, along with Sara Packer, were both recovering from suicide attempts and that he was not of sound mind at the time of the confession.

Bucks County detective Timothy Carroll shared the circumstances of Sullivan’s confession at a pretrial hearing on Tuesday.

The detective said in court that officers were called Abington Memorial Hospital after Sullivan told hospital workers about the killing.

When police arrived to the hospital, Carroll said that Sullivan did not seem surprised to see them, and that he was forthcoming about Grace’s murder although he had been uncooperative in the past when questioned.

“He did in fact describe how Grace Packer was killed and where she was killed. He knew things that I knew or believed to be true,” Carroll said. Sullivan also said that Grace was killed in fulfillment of a rape-murder fantasy Sara Packer and Sullivan Shared.

As CrimeOnline previously reported, Sullivan is accused of bring Grace to the home with Sara Packer, where he hit, raped and drugged the developmentally challenged teenager before stuffing her in a hot cedar closet overnight, expecting her to die. When she was still alive the next morning, Sullivan allegedly suffocated her. The couple allegedly kept Grace’s body packed in cat litter in the home until October, when police visited the house. They then allegedly chopped up the body in the bathtub before tossing the remains in a remote wooded area, where they were later found by hunters.

“He seemed to be wanting to get it off his chest at that point,” Carroll said of Sullivan’s confession.

A judge has yet to rule whether or not the confession will be admitted at Sullivan’s trial.

Packer and Sullivan are expected to be tried separately, unless Packer pleads guilty.

[Feature image: Bucks County Sheriff: Sarah Packer/Grace Packer/Jacob Sullivan]