Police say an autopsy has determined that two Vermont brothers found dead last month in a Burlington apartment died of "fentanyl intoxication."
Police are offering substantial cash reward for information leading to an arrest of the person or persons responsible for distribution of the lethal dosages of fentanyl - an opioid drug that is up to 50 times more powerful than heroin.
Shortly after the deaths of 32-year-old Sean Thibault of Westford and 34-year-old Dennis Thibault of Burlington, who were found unresponsive at the home on June 18, police said they found evidence of heroin and fentanyl.
Burlington police say there has been an "alarming" increase in drug overdoses this year. Police believe heroin is increasingly being laced with fentanyl.