Oklahoma County District Attorney David Prater is speaking out against a possible reduction to the life sentence handed down to a former metro pharmacist sentenced for murder.

Jerome Ersland claimed he was acting in self-defense in the May 2009 when he shot and killed 16-year-old Antwun Parker during an armed robbery attempt inside his store.

Legal experts say Ersland's actions morphed from self-defense to vigilantism and that there is little chance his sentence will be reduced, the Associated Press reported on Saturday.

Prater sent the following letter to the Oklahoma Pardon and Parole Board, regarding Ersland, on April 6: