The Massachusetts chief medical examiner's office says former state Sen. Brian Joyce died from an overdose of a medication commonly used to treat insomnia.
The medical examiner's office said Tuesday the 56-year-old Democrat died of acute pentobarbital intoxication, but they were unable to determine if his death was an accident. Pentobarbital is a sedative.
Joyce was found dead by his wife at his Westport home in September. The Bristol District Attorney's office said at the time no foul play was suspected.
Last year, Joyce had pleaded not guilty and was awaiting trial on federal corruption charges, including racketeering, extortion wire fraud and money laundering. Prosecutors said Joyce had profited off his position by accepting up to $1 million in bribes and kickbacks and laundered the money through his law office.
Joyce was first elected to his Senate seat in 1988.
Court records show U.S. Attorney Andrew Lelling dismissed charges against Joyce in October, citing his death.