Calling 18 pounds of crystal meth­am­pheta­mine a huge amount of drugs, but taking into consideration the youth of the Los Angeles man who carried it in a backpack, a federal judge in Hono­lulu sentenced him to about four years in prison for his role in a Hawaii drug ring.

U.S. District Judge Helen Gillmor sentenced Antonio Perez Jr. to 51 months in prison Thursday. In spite of the quantity of the drugs involved, Gillmor said that because of his youth and his lack of previous criminal convictions, and because he comes from a good family, the sentence is far lower than what she could have imposed.

Perez, 22, previously pleaded guilty to charges that he was involved in a drug-trafficking ring. According to court documents, another man brought the meth when he flew from San Diego to Hono­lulu last year. Perez’s plea agreement says he met that man in a Wai­kiki hotel, where Perez loaded his backpack with 18 pounds of meth.

The agreement says Perez carried the backpack to a Wai­kiki apartment, where he hid the drugs in a clothes dryer. Authorities also found $102,000 in cash in the apartment when they found the drugs.

The amount of drugs and cash involved revealed the type of conspiracy Perez was part of, said Assistant U.S. Attorney Tony Roberts. "It’s a big operation," Roberts said.

The estimated Hono­lulu street value of 18 pounds of crystal meth is $360,000.

Perez told the judge Thursday that he was addicted to marijuana and alcohol when he ended up in Hono­lulu trying to earn money to help his family. Reading from a handwritten statement, he apologized.

Gillmor said she doesn’t buy Perez’s reasons for getting involved in a drug ring. "I don’t think couriering 18 pounds of drugs was based on altruistic reasons of helping your dad," she said.

Defense attorney Myles Brei­ner said Perez had no control over the quantity of the drugs he carried. "He didn’t deal drugs; he didn’t sell drugs," Brei­ner said. "My client was a courier."

One co-defendant in the case has also pleaded guilty, and another is scheduled to go to trial in December.

By Jennifer Sinco Kelleher, Associated Press