New Hampshire's Supreme Court is set to hear arguments in the appeal of a Vermont man convicted of negligent homicide in the 2010 gunpowder plant explosion in Colebrook that killed two workers.
Craig Sanborn of Maidstone, Vermont, was sentenced to 10-20 years in prison after being convicted in 2013 in connection with the deadly explosion at his Black Mag gunpowder plant.
Sanborn's lawyer is challenging the credibility and background of a witness who did business with Sanborn, among other issues raised on appeal.
Killed in the explosion were 56-year-old Donald Kendall, of Colebrook, and 49-year-old Jesse Kennett, of Stratford.
Sanborn also was convicted last year of wire fraud for submitting false invoices to the town of Brownville, Maine, and was sentenced to 28 months.
The justices hear arguments Thursday.