An Augusta man suspected of holding up a Hallowell bank last month is in federal custody.

John Cecil Slater, 66, is scheduled for a hearing at noon Thursday in U.S. District Court in Bangor on a charge he robbed the Bank of Maine on Winthrop Street on June 23.

Hallowell Police Chief Eric Nason said Slater was arrested in New Hampshire.

It was not immediately clear which agency made the arrest, but the court docket indicates it happened Wednesday.

Investigators had been seeking the public’s help in finding Slater, whom they described as armed and dangerous.

Documents unsealed after Slater’s arrest show investigators found paper similar to that used to write the bank robbery demand note in Slater’s apartment in Augusta.

The note said, “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.???”

Along with the random capitalization, several words were underlined.

The text was included in an affidavit filed in federal court by FBI Special Agent Glenn D. Barnes.

The affidavit says the robber fled the bank with $15,000 in $100 bills.

Slater, who as an extensive criminal history, was later identified as the suspect through surveillance photos from the bank.

State and federal records indicate Slater has dozens of convictions across the midcoast and central Maine dating back to 1978. Slater, who in 1995 was convicted of two counts of gross sexual assault, is a lifetime registrant on the Maine Sex Offender Registry. He was sentenced in Somerset County Superior Court in August 1995 to 14 years in prison, with all but seven years suspended, for raping two children, one of whom was younger than 14.

The bank robbery occurred at 10:15 a.m. June 23 when a neatly dressed older man told tellers at the bank at 14 Winthrop St. he had a live grenade and demanded money.

Nason said shortly afterward that the man asked to open an account, then handed over a note that made a threat and demanded money. He did not show a weapon, and he left on foot, walking down Winthrop Street.

The robber was described as a man in his late 60s or early 70s, roughly 6 feet tall and about 175 pounds; wearing a straw hat, a brown suit jacket, a blue shirt, tan or brown pants and brown shoes; and carrying a brown briefcase.

Investigators received calls identifying Slater as the suspect almost immediately after the photos from the bank surveillance were broadcast on the news and on the Internet.

Some callers said they were briefly friends of Slater, and one caller identified as an employee of a credit union in Augusta reported recognizing Slater as a customer. That person told FBI agents Slater had a credit union account that frequently was overdrawn and that he “was living month-to-month on disability income,” Barnes wrote.

Several others said they had ended friendships with Slater after discovering he was a sex offender. Another caller said Slater said he had a brain tumor.

They also described him as a disabled veteran with his left hand “permanently curled like a hook.”

Another caller said Slater had asked for help moving items from his home at Capri Apartments in Augusta to a trailer in Gardiner, according to Barnes’ affidavit.

Later, investigators spoke to Slater’s payee — someone “contracted by the Veterans Administration to administer Slater’s veteran benefit because Slater has been declared incompetent to handle his own money,” Barnes wrote — who paid a deposit for Slater on a lease on Marston Road in Gardiner.

Maine Department of Motor Vehicle records showed Slater drove a 2014 silver Dodge Journey, and investigators found the vehicle at the Gardiner address and found in it “a Panama Jack-style hat, a brown accordion-style briefcase, a brown men’s blazer, and black sunglasses” as well as a pair of latex gloves.

In a search of Slater’s Augusta apartment, investigators seized a box of .32-caliber Smith & Wesson ammunition as well as a Bank of Maine cash bag.

Court records indicate attorney William S. Maddox will be representing Slater at Thursday’s hearing before Magistrate Judge John C. Nivison. The prosecutor is Assistant U.S. Attorney F. Todd Lowell.

A federal bank robbery conviction carries a maximum penalty of 20 years in prison.

Betty Adams — 621-5631

badams@centralmaine.com

Twitter: @betadams