WOODBURY — A 25-year-old Pitman man pleaded guilty Monday to operating a meth lab in a shed behind his parents’ Columbia Avenue home.

Ari Lleshi also admitted he was in possession of a hallucinogenic drug when he was stopped in a vehicle in Mantua in March 2014. He acknowledged the two 2014 offenses violated the probation he’d been given in 2011 for aggravated assault and burglary charges, authorities said.

In the negotiated plea, Assistant Gloucester County Prosecutor Dianna Reed-Rolando will recommend Lleshi be sentenced to four years in state prison on the meth case,  to which he pleaded guilty pre-indictment, said authorities.

The sentence recommendation for the Mantua drug case and the probation violations will be three-year prison terms to run concurrently with the four-year term.

According to complaints, Lleshi had about 1.5 ounces of meth and was putting it into a backpack in the shed that appeared to be his lab when police arrested him on June 13, 2014, authorities said.

In entering his plea Monday, Lleshi said he knew that making methamphetamine was illegal, said authorities.

Sentencing has been scheduled for May 22. Lleshi will remain free on $50,000 bail, on the condition he enroll in drug rehab for his admitted meth addiction.