New details point to a possible premeditated plot in the family murders at Great Wolf Lodge in Pennsylvania, a private investigator says.

Metallica Rose Harrison, 27, is facing two counts of criminal homicide after prosecutors say she stabbed and killed her husband, Charles "Chaz," and the couple's 3-year-old son, Tristan. It happened at the resort in the Poconos region of Pennsylvania.

According to a criminal complaint, knives recovered by investigators on scene did not match knives belonging to the resort.

The document says, "Both knives had teal green handles, which Great Wolf staff confirmed was not a type kept by the lodge." STEPMOM SAYS GREAT WOLF LODGE MASSACRE SUSPECT DRAINED FAMILY'S 401(K) BEFORE PRICEY WEEKSLONG STAY The family has confirmed that autopsies for both victims were being conducted. Investigators discovered the father and young son slaughtered in a hotel room at the resort on Monday.

Send me a story idea: kelsie.cairns@fox.com kelsiecairns_tv Kelsie Cairns TEACHER FOUND DEAD WITH THROAT SLIT; DETECTIVES SCRUTINIZE HUSBAND’S SHIFTING STORY Harrison's stepmother told Fox News Digital it's possible that the suspect may have drained the family's 401(k) account ahead of the three-week stay at the resort.

The family of three lived in a modest home in Towanda, Pennsylvania. Their home is around 100 miles northwest of the resort.

WOMAN ACCUSED OF DEADLY REVENGE CRASH FACES JURY AS BOYFRIEND’S HOSPITAL ACCOUNT STAYS OUT OF TRIAL "There’s so many lodges up in the mountains between where they lived and where they went to, that I’d be curious as to why they picked that lodge," said private investigator Rod Devine. His firm is based in the Lehigh Valley area of Pennsylvania, south of the Poconos. "There’s a lot of moving parts here that the investigators will be looking at," he said. In his experience, he has sat face-to-face with convicted killers and homicide suspects.

'AMERICAN IDOL' ALUM CALEB FLYNN CONVICTED OF MURDERING HIS WIFE He explained that the allegations of the drained retirement fund, the nature in which both the husband and toddler were killed, and the possible murder weapons brought from home on the lengthy vacation suggest possible premeditation in the horrific case.

MAN UNLEASHES DEADLY ‘REVENGE’ RAMPAGE ON EX’S FAMILY, KILLS 4 PEOPLE, 3 DOGS BEFORE TORCHING HOME: DA "From the cursory file that we can look at, we being the general public, it looks like there are certain elements that are already met," he said.

Harrison's stepmother previously told Fox News Digital the killings appeared to be "preplanned." Various news outlets also report that Harrison never wanted to be pregnant in the first place and was allegedly resentful toward her own son.

GET BREAKING NEWS BY Why? Reports say she wanted more alone time with her husband.

Family also allegedly told investigators that the mother accused of the killings "was dominant, controlling and isolated the three of them from her husband's family for the last three years," WNEP reported. While the investigation into the killings continues, Chaz's family members grapple with their new normal." His love for his wife and child was out of this world and, sadly, is the reason why he lost his life and his son's life," Chaz's sister shared in an update on a GoFundMe page.

SEND US A TIP "I’m not here to say anything bad about his wife. I know my brother would not want me to do that," she went on to say. She is sitting in a Monroe County jail cell and due in court on Oct. 21.