Colin Haag III is facing a criminal homicide charge in connection with the death of cousin Autumn Bartle

A 20-year-old Pennsylvania man has been charged in the brutal slaying of his 14-year-old cousin, who died days after being stabbed more than 80 times and shot in the head, PEOPLE confirms.

A motive remains unclear.

Colin Haag III is facing a criminal homicide charge in connection with the death of cousin Autumn Bartle, according to Bucks County District Attorney Matthew Weintraub.

Autumn died from her injuries on April 2, three days after her mother found her unconscious and bleeding on the living room floor of the family’s home in Bristol Township. The girl was suffering from dozens of stab wounds and a gunshot to her left temple, authorities say.

Investigators believe Autumn was attacked in a bathroom in the home, leaving it covered in blood and handprints.

It was “apparent that Autumn Bartle, with bloodied hands, had attempted to climb out of the window and escape, but was unsuccessful,” states a probable cause affidavit in the cause, which was obtained by PEOPLE.

Haag, Autumn’s cousin, was living with her family at the time but wasn’t home when Autumn’s body was discovered. He was arrested Wednesday in nearby Bensalem Township after his description was circulated statewide.

Police say ballistics evidence allegedly connects him to the crime, according to the probable cause affidavit. What’s more, authorities claim they recovered Autumn’s blood from a notebook in Haag’s backpack when he was taken into custody.

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Credit: GoFundMe

At the time, Haag was allegedly found walking alongside a road in Bensalem with his bag and then tried to flee as officers started walking toward him, the affidavit states. He allegedly shot himself in the throat as authorities neared.

“The defendant stated that he shot himself because he didn’t want to go to jail,” reads the affidavit.

Haag was treated for his gunshot wound and is being held at the Bucks County Correctional Facility in lieu of $100,000 cash bail.

He is charged with criminal homicide, aggravated assault, burglary, kidnapping, unlawful restraint of a minor, receiving stolen property, carrying a firearm without a license and possessing an instrument of crime.

Haag has yet to enter a plea to the charges against him and does not have an attorney of record who could comment on his behalf.

Credit: Bucks County District Attorney's Office

Asked about a suspected motive in the killing, Weintraub told reporters on Friday it was still under investigation, according to

“We hope to have that answer,” he said. “We’ll continue to work on getting that answer. But sometimes, as we stand here in this case, you look into the face of a killer and you don’t get answers. You see only darkness.”

A GoFundMe campaign has been started to help financially support Autumn’s funeral. Her organs were donated by her family, Weintraub said.

“Even in death, Autumn and her mom and her dad gave others the gift of life,” he said. “That was a very courageous decision.”