A New Hampshire firefighter pleaded guilty to a string of arson charges on Wednesday following a four-year investigation into a serial arsonist starting fires across Rockingham County.
Austen M. Cooper of Raymond, NH, a firefighter, pleaded guilty to three counts of felony arson to real estate and one count of felony possession of an infernal machine.
The NH State Fire Marshal’s office began a complicated investigation into serial arson across Rockingham County.
The investigation led fire marshals to believe Cooper intentionally set brush fires on the Rockingham Recreational Trail in New Hampshire and in the John B. Folsom Conservation Land in Epping between April and May 2022.
He also set fire to a structure at Raymond’s Welch Baseball Fields on July 30, 2022.
The infernal machine possession charge sprang from the Epping incident when an incendiary device was discovered on the scene of the blaze.
He was a certified NH firefighter at the time of the arson incidents and previously lived in Huntingburg, Indiana.
He was arrested in Indiana in December 2025 by U.S. Marshals and extradited back to NH.
He was sentenced to 19 months in prison, with 14 months remaining on his sentence. He will be on probation for ten years after his release from prison and will face up to five additional years in prison if he violates his conditions of release.
Those conditions prohibit Cooper from applying to work as any sort of emergency first responder.
The Fire Marshal’s office is petitioning for the removal of Cooper’s firefighter certification.
