A federal prosecutor is asking that accused Hallowell bank robber John Cecil Slater remain in custody because he is a flight risk.

Slater, 66, of Augusta, was arrested without incident about 1:10 p.m. Wednesday by the Boston Division of the FBI and Maine State Police, in Twin Mountain, New Hampshire. On Thursday, he waived his right to a preliminary hearing.

He is charged with the June 23 holdup of the Bank of Maine on Winthrop Street in Hallowell, and an affidavit says the robber told bank employees at least twice that he was armed with a live grenade.

The prosecutor, Assistant U.S. Attorney F. Todd Lowell, sought to have Slater detained, indicating to Magistrate Judge John C. Nivison that there is probable cause to believe Slater committed the holdup and will be subject to a lengthy prison term if found guilty.

“There is also a serious risk that the defendant will flee,” Lowell wrote. “The defendant abandoned his residence in Maine shortly after the bank robbery. … There is no condition or combination of conditions that will reasonably assure the defendant’s appearance as required and the safety of the community.”

When investigators initially identified Slater as a suspect and began searching for him, they described him as armed and dangerous.

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.

Slater made an initial appearance in court Thursday before Nivison, and Slater waived his right to a preliminary hearing through a document signed by him and his defense attorney, William Maddox.

Later on Thursday, Maddox said a detention hearing for Slater might be held at a later date. He said Slater suffers from post-traumatic stress disorder and other service-related ailments.

“I’m still at the very early part of my investigation,” Maddox said. “All I can say at this point is that he has been found 100 percent disabled by the Veterans Administration and he suffers from PTSD from Vietnam where he was shot – wounded in the shoulder. Also, he was afflicted with Agent Orange.”

Documents unsealed after Slater’s arrest revealed that investigators who searched his Augusta apartment found paper similar to that used to write the note demanding money and threatening violence.

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 – rob, silent and alarms – 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.

The bank robbery occurred at 10:15 a.m. June 23 when a man handed over the note after telling workers at the bank at 14 Winthrop St. that he had a live grenade and demanded money. He did not show a weapon and fled on foot.

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. Police said those items were later found in Slater’s car, and ammunition was found in his Augusta apartment. Slater told friends he was in the process of moving to a trailer in Gardiner, and that’s where investigators found the car.

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

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.

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

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