BANGOR, Maine — A convicted sex offender pleaded guilty Tuesday in U.S. District Court to one count of bank robbery.

By pleading guilty, John Cecil Slater, 66, of Gardiner admitted that he robbed the Hallowell branch of the Bank of Maine at around 10:15 a.m. June 23 of $15,000.

Slater, who has been held without bail since his arrest on July 9 in Twin Mountain, New Hampshire, by members of the FBI’s Boston Division and Maine State Police, was identified by several people who recognized him in a surveillance photo released to the media.

His sentencing date has not been set.

Slater is required to register as a sex offender for life due to a conviction in Somerset County Superior Court in 1995 for gross sexual assault of a minor and gross sexual assault of a minor in his care.

When he entered the bank in June, Slater wore a straw hat, sunglasses and a tan sports coat and asked to open an account, according to court documents.

Slater handed a bank employee a note that read: ” Im Here to Rob your Bank, no silent Alarms my cell phone rings, your all dead, I have a hand grenade, and a gun, no marked bills, or inked, if so, one day I will come back and kill all of you, do you understand.???”

After passing the note, the bank robber told the teller, “I’m sick. I want $15,000 in $100 bills. I don’t care, I’ll shoot.” The bank employee informed the bank manager that the bank was being robbed and the two provided the cash to Slater, who then left the building, court documents said.

Slater faces up to 20 years in federal prison and a fine of up to $250,000. He also could be ordered to pay restitution to the bank and forfeit a motorcycle the indictment alleged he bought with the stolen money.

BDN writer Nok-Noi Ricker contributed to this report.