Eleven years ago, Dufresne's second husband was found dead in their Goffstown, N.H., home. An autopsy revealed that Lawrence Blackwood died from ingesting antifreeze "over a period of time." Dixie cups full of the liquid were also found in his bathroom.
Blackwood's death was ruled a suicide.
"Nothing suspicious in nature was found," Robert Browne, a spokesperson for the Goffstown Police Department, told ABCNews.com. Browne said in light of Dufresne's charge, there were no plans to reopen the Blackwood case.
"If information as such exists right now and is forwarded to us, we would make sure the attorney general's office was aware of it," he said.
A woman who answered the phone at Dufresne's home said the family had no comment.