Pennsylvania Killing Spree Suspect Poisoned Himself, Autopsy Reveals

Bradley Stone allegedly shot and killed six members of his family.

— -- The death of Pennsylvania killing spree suspect Bradley William Stone has been deemed a suicide by poisoning, authorities said today.

The body of Stone, 33, who the district attorney said killed six of his relatives, was found in a wooded area outside of Pennsburg, near Philadelphia, on Dec. 16 after a manhunt. Police found two knives, a machete and a double-bladed axe near his body, which had multiple self-inflicted wounds, authorities said.

But after an autopsy, the coroner determined that the cause of death was due to a "combined drug intoxication" resulting from a cocktail of drugs -- Trazodone, Risperidone and mCPP -- and that the manner of death was suicide, authorities said.

The killing spree had prompted local and federal authorities to launch a manhunt in the suburbs of Philadelphia.

The motives for the murders remains uncertain, but legal documents indicate that Stone and his ex-wife, one of his alleged victims, had been having custody issues over the control of their 5- and 8-year-old daughters.

Stone and Nicole Hill divorced in March 2009 and Montgomery County court documents show that they reached a shared custody agreement in April 2010 but there were some disputes over the arrangement in the years since.

The details from the documents are not publicly available, but earlier this month, Stone filed an emergency motion seeking custody. There was a resolution in the case on Dec. 9 but the specifics of that agreement were not available.

The district attorney said that the court documents indicate that the couple had a "contentious, protracted" custody battle and the recent decision ruled in favor of his ex.