A former U.S. Postal Service clerk on Hawaii island is going to jail for seven days for stealing mail while working at the Volcano Post Office.

Vicente Martinez, 61, pleaded guilty in April to two counts of stealing mail that contained gift cards.

Investigators caught Martinez in a sting operation. When they confronted him, Martinez admitted that he stole mail containing gift cards seven to 10 times, two parcels containing clothes and other mail containing cash, said federal prosecutor Tracy Hino.

U.S. District Chief Judge Susan Oki Mollway sentenced Martinez to the jail term July 28. She also ordered him pay a $1,000 fine, reimburse the intended recipient of the gift cards $150 and perform 100 hours of community service.

Martinez has until next month to begin serving his sentence.

He apologized for what he did and said he knows he let a lot of people down.

“I was proud to be a mailman,” Martinez said, “I failed my co-workers, I failed my boss. I brought shame to my family, my kids.”

Authorities started investigating Martinez after the person who sent the gift cards realized he had placed the wrong ZIP code on the envelope and notified the Postal Service.

Hino said letters and parcels sent to the wrong Post Office by automated sorting machines are difficult to track, leading Martinez to believe that he committed the perfect crime. He said if mis-sorted mail is tracked, it is to the postal carrier, not to the person, like Martinez, who is supposed to reprocess the letter or parcel to get them to the correct address.