A Hiram man convicted of killing three family members in 1996 died Tuesday morning at the Mountain View Correctional Facility in Charleston.

Dennis Vanwart, 71, died at approximately 2 a.m., according to a release from the Maine Department of Corrections. Vanwart began serving a 60-year sentence for murder in 1996, according to MDOC spokesperson Anna Black.

Vanwart was convicted of fatally shooting his 71-year-old mother, 73-year-old father, and 45-year-old brother.

At the time of the murders, Vanwart worked as a dog groomer. Neighbors described him as an odd, reclusive man who lived with his family and collected snakes that he stored in a freezer.

During his trial, Vanwart pleaded innocent by reason of insanity, a plea that was rejected by the presiding judge.

The Maine Department of Corrections typically does not comment on an inmate’s cause of death. Any deaths caused by COVID-19 are included in case counts maintained by the Maine Center for Disease Control and Prevention.

There have been at least two other deaths at Mountain View Correctional Facility within the last year.

Robert Craig 86, of Clearwater, Florida, who was convicted of murdering his friend in 2017, died Dec. 4. Harold Glidden, 74, of East Holden died at the prison in August 2021. Glidden was serving a 70-year sentence for killing a 19-year-old hitchhiker in the early 1980s.