RCMP have charged two Nova Scotia men with a serious assault against an inmate at the Maritimes' only maximum security prison, the Atlantic Institution in Renous, N.B.

James Bernard Melvin, 38, and Morgan James McNeil, 29, are each facing two charges of aggravated assault for an incident on Sept. 26.

Details of the incident have already been revealed as part of sentencing arguments against Melvin, a notorious crime figure in the Halifax area.

The Crown is trying to have Melvin declared a dangerous offender following his conviction on charges of attempted murder and conspiracy to commit murder related to an attempt on the life of Terry Marriott Jr. in 2008.

During sentencing arguments last month, Nova Scotia prosecutors said Melvin attacked Joshua Preeper in an exercise yard at Renous. According to the evidence, Melvin knocked Preeper to the ground and repeatedly stomped on his head and kicked him before guards could intervene.

In announcing the charges against Melvin and McNeil on Wednesday, RCMP said Preeper remains in hospital with serious but non-life-threatening injuries.

Preeper and his brother, Dustan, are each serving life sentences for the murder of Melissa Dawn Peacock in 2011. The brothers admitted to stabbing the 20-year-old woman, then dousing her body in gasoline and setting it on fire.

McNeil is serving a seven-year sentence for manslaughter for his part in the killing of 21-year-old Laura Jessome in 2012. Her remains were found in a hockey bag in the Mira River in Cape Breton.

McNeil and Melvin are due to appear in a New Brunswick court in February.