Glenn Guyn, 49, of Mount Hermon, was sentenced Monday as a multiple offender to 40 years in prison for operating a methamphetamine lab in his home, according to information released by District Attorney Warren Montgomery’s office.

A Washington Parish jury found Guyn guilty of the crime on Oct. 13.

The Washington Parish Drug Task Force was working in the Mount Hermon area on March 14 when officers stopped a vehicle that was being driven erratically by Guyn. During a search of the vehicle, officers discovered plastic bags that contained powder, which was later determined to be methamphetamine. Officers then obtained a search warrant for Guyn’s home, where they discovered items used in the production of methamphetamine.

The jury found Guyn guilty of possession with the intent to distribute methamphetamine and creating and operating a clandestine lab for unlawful manufacturing of methamphetamine. Guyn pled guilty to armed robbery in 1989 and also has prior convictions for possession with the intent to distribute methamphetamine, possession with the intent to distribute marijuana, and possession with the intent to distribute hydrocodone and Alprazolam.

Assistant District Attorney Nick Noriea handled the case before District Judge Richard A. Swartz Jr.