BELFAST — A joint police investigation has led to the arrest of three Belfast residents in connection with the armed robbery of Gillen’s Market in Winterport last spring.

Charged with armed robbery and three counts of burglary, including the theft of the firearm used in the robbery, was Richard A. Morse III, 21. His 41-year old aunt, Cheryl Peckham, whom police believe drove the getaway car, also was charged with armed robbery. The third suspect, Heidi Hyson, 19, was charged with taking part in the theft of the black-powder handgun used in the robbery of Gillen’s.

Maine State Trooper Glenn Lang credited the trio’s apprehension to good fortune and cooperation between police departments. The Waldo County Sheriff’s Department and Belfast Police Department each played a part in the arrests.

Gillen’s was robbed at gunpoint at about 10 p.m. March 11 by a man disguised as a woman. The store clerk told authorities that robber was wearing heavy makeup, a long black coat, black hat and boots. Although the robber appeared to be a women, the clerk said the person spoke in a deep voice after pulling a gun from a handbag and ordering him to hand over the contents of the cash register.

Lang said the case broke Monday when he received “a tip from a person who said he knew who was involved.” Lang said that when he and Trooper Tom Ballard relayed what they had learned to Waldo County Sheriff Detective Scott Storey, the information checked out.

“Certain things matched up,” Lang said. “One of these people was bragging about doing the robbery.”

After reviewing their information with the District Attorney’s Office on Tuesday, Lang and Ballard notified Belfast police about whom they were seeking. Police Chief Robert Keating arrested Morse on Waldo Avenue a short time later. Peckham was arrested by Lang and Ballard after she went to the police station to inquire about Morse. Hyson was picked up at her residence later Tuesday night.

The trio was booked at the Waldo County Jail and bail was set at $50,000 with sureties or 50 percent cash. Peckham and Hyson were later transferred to the woman’s facility at the Knox County Jail while Morse stayed at Waldo County. All three remain in custody.

“All the departments helped out,” Lang said. “It was a real joint effort. Things worked out really well. There’s a lot of cooperation between departments in Waldo County.”