Isaiah Sweet is charged with two counts of first-degree murder. He is accused of killing his grandparents and legal guardians, Janet, 62, and Richard, 55, Sweet, of Manchester, who were found dead in their home May 13, with gunshot wounds to the head. Relatives found the bodies when they came over for Mother’s Day.

According to a search warrant, Isaiah Sweet admitted to shooting his grandparents after contemplating beating his grandfather with a baseball bat. He has pleaded not guilty to those charges and remains in the Buchanan County Jail under bond.

Isaiah Sweet is also accused of assaulting a girl with the intent to sexually abuse her in April, before the homicide involving his grandparents. He has pleaded not guilty to assault with intent to commit sexual abuse causing bodily injury and misdemeanor charges of possession of drug paraphernalia, possession of alcohol under legal age, trespassing and operating a motor vehicle without owner’s consent.

Delaware County Attorney John Bernau said the murder and assault charges will be handled in one trial. Bernau has declined to give details about the assault or the alleged victim.

Brandon Ahlers, 19, of Manchester, was also charged in the homicide of Janet and Richard Sweet with two counts of aiding and abetting in first-degree murder.  He is accused of suggesting to Isaiah Sweet ways to kill the couple. He has pleaded not guilty and his trial was reset to Dec. 12.