An Amherst man pleaded guilty in court Wednesday to what federal prosecutors call the biggest synthetic marijuana bust in Western New York history.

Fawzi A. Al-Arashi, 35, pleaded guilty before U.S. District Judge Richard J. Arcara to conspiracy to possess with intent to distribute a controlled substance.

Al-Arashi was charged last July, after a search of his warehouse on Ridge Lea Road in Amherst turned up 30,000 packets of the drug.

He will be sentenced on Nov. 25.

“To the best of our knowledge, this is the first conviction here in Buffalo involving synthetic marijuana,” said U.S. Attorney William J. Hochul Jr.

The case, in fact, raises the question of how stiff a penalty the judge should impose.

Synthetic marijuana is still new enough to the scene that both sides differed widely Wednesday on where this crime falls within the sentencing guidelines.

Defense attorneys compare the drug to marijuana and, based on the guidelines, believe it means as much as 2½ years behind bars at the most.

The U.S. Attorney’s Office, meanwhile, thinks synthetic pot should be treated differently than marijuana because it’s a more potent, more dangerous drug, Hochul said.

Federal prosecutors believe that as many as 14 years behind bars is more appropriate in this case.

“So either way it’s going to be appealed, I’m sure, no matter how we calculate this?” Arcara asked in court.

“I don’t think so,” said Joel L. Daniels, who is representing Al-Arashi, along with defense attorney Cheryl Meyers-Buth.

Al-Arashi was born in Yemen, but grew up in the Buffalo area, where he graduated from the University at Buffalo with degrees in computer science and business administration, he told Arcara.

He operates several family-owned convenience stores in the area, Al-Arashi told the judge.

The Drug Enforcement Administration Office in Buffalo was tipped off by the DEA office in Los Angeles last year about a suspected shipment of synthetic marijuana bound for Western New York, U.S. Assistant Attorney Frank T. Pimentel said in court Wednesday.

The shipment was delivered to Town Tobacco, Al-Arashi’s store at 3407 Delaware Ave., Town of Tonawanda.

But law enforcement said the operation was much bigger than Town Tobacco or Al-Arashi’s other store, Welcome, Welcome, at 140 Main St., North Tonawanda.

Al-Arashi is accused of repackaging the synthetic marijuana at his Amherst warehouse then selling it across the state in brightly colored packages with such names as “Pump It,” “Tiger Shack” and “California Dreams.”

Daniels declined to comment outside the courtroom on Wednesday.

Al-Arashi already has agreed to forfeit nearly $300,000 from three accounts, as well as a 2012 Ford Tundra, Pimentel said.