A 33-year-old Vineyard Haven man was indicted by a Dukes County grand jury last week on felony charges in a case that involves a fatal overdose from the powerful drug fentanyl.

On Oct. 18 Jason Willoughby was indicted on charges of involuntary manslaughter, distribution of a class B substance (fentanyl) and conspiracy to violate drug laws. The case dates to February of this year when Mr. Willoughby was arrested several days after police had been called to a home in Vineyard Haven where a woman was found dead of an apparent overdose. A police report said an investigation found that Mr. Willoughby sold the woman the drugs that caused the overdose.

Mr. Willoughby was arraigned in Edgartown district court on Feb. 6 on a charge of distributing a class B substance (fentanyl).

Fentanyl is a powerful synthetic opioid used in hospitals as an anesthetic. It is sold illegally mixed with heroin or cocaine and is believed to be the cause of an increase in fatal overdoses in recent years throughout New England, including on Martha’s Vineyard.

No date has been set yet for arraignment on the new charges in superior court.