The parents of John Granat, 17, allegedly discovered several weeks ago that the Palos Township teen had been growing marijuana in their home, a source close to the investigation told the newspaper.
Granat was ordered held without bond Tuesday in the deaths of his parents, John and Maria Granat, whose bludgeoned bodies were found Sunday morning in the bedroom of their large suburban home, the Tribune said.
Cook County Sheriff Dart said Granat offered several conflicting alibis to his location prior to his parents' deaths.
"It was clear that [Granat] had a difficult relationship with his parents at times and at different times had made threats," Dart said after Tuesday's hearing. "[Granat] gave numerous stories, one after the other, including alibis. None of which made any sense, none of which turned out to be true."
The Tribune's sources said his friends pleaded with the teen him not to kill his parents.