LAGRANGE, Ky. (WHAS11) -- The night of Feb. 5, 2012 still haunts David and Jennifer Williams and not only because it's the night their 16-year old daughter Summer Williams died. They also want to know how and why it happened.
The Oldham County High junior was staying one Saturday night with a friend but didn't wake up the next morning. Toxicology reports reveal a lethal mix of four drugs, including the painkiller Opana and an ingredient in cold medicine that gets users high. Summer's mother, Jennifer, says she was also taking other prescriptions.
Thursday, six months after Summer's death, La Grange Police arrested four people in connection with her death: Roger Wilson, Tiffany Dull, Tiffany Richardson, and Phillip Kinser. All were charged with unlawful transaction with a minor, a felony. Kinser was also charged with trafficking a controlled substance.
Summer's parents say they believe the group sold her an Opana pill and they all shared it.
They also say Richardson is Summer's boyfriend's Mother but her boyfriend was not involved.
The owner of the home where Summer was found dead, Vance Subsequently, told WHAS11 he left the two girls alone to go roller skating in Okolona and returned later that night to find them both sleeping.
Vance says Summer left the home during the time he was away to hang with others and that his daughter stayed home.
He says his daughter was frantic the next morning and that he was unable to perform CPR at the scene.
Wilson, 18, told WHAS11 at his home after he bonded out of jail that Summer's death was her own fault, because she was 16, she could make her own decisions, and wasn't influenced by anyone.
The other three suspects are in the Oldham County Jail.