A police officer surveilling a Portland address last weekend as part of a drug investigation helped lead detectives to a man they believe was responsible for a string of recent local robberies.

Details about how police found and arrested Joseph Evers, 41, were contained in an affidavit filed Wednesday in Portland Unified Criminal Court ahead of his first appearance before a judge on three counts of felony robbery.

Police allege that between Dec. 4 and Dec. 10, Evers robbed the CVS pharmacy on Forest Avenue and a TD Bank on Congress Street in Portland, and the Key Bank on Route 1 in Falmouth. In each case, the suspect threatened violence but did not show a weapon.

Investigators also believe Evers was responsible for attempted robberies at the Domino’s Pizza on Forest Avenue and the Walgreens Pharmacy on Marginal Way in Portland. But he was charged only with misdemeanor theft in the Walgreens incident, where he allegedly stole a bag of M&Ms after a clerk told him there was no money in the drawer and that he should leave, and the two exchanged profanities.

Evers’ attorney for the day, Cory McKenna, argued that the trail of clues that led to Evers was not strong enough to charge him, but Justice Nancy Mills said the police work showed a sufficient connection. Mills ordered Evers held on $10,000 bail, or $3,000 if he agrees to abide by conditions of a pre-trial release contract to abstain from drugs and alcohol, obey a curfew and stay away from the businesses he is charged with robbing.

No charges were filed in connection with the Domino’s incident. In that case, police say, someone entered the fast-food restaurant Dec. 5 and demanded money but employees did not hand over any cash. The would-be robber left the counter in frustration, driving toward downtown Portland in a Honda SUV with a Florida license plate. Evers still could face charges in that case.

Prosecutors must go before a grand jury to seek indictments on the three felony robbery counts, and could choose to present evidence in the attempted hold-ups.

Evers, who appeared from a jail cell via Zoom, did not speak during the hearing, except to acknowledge that he understood the allegations against him. He has no criminal history in Maine, where he has lived for eight years, works full-time and helps maintain hiking trails in his spare time, McKenna said. Evers did not answer questions when arrested in Falmouth, and police did not suggest a motive.

Assistant District Attorney William Barry said Evers has a history of contact with police in Florida in situations involving drugs. But McKenna said Evers was never convicted of a crime in Florida.

Police linked Evers to the Maine crimes using surveillance footage they collected after the Dec. 6 robbery of the TD Bank in the Westgate Shopping Center.

The footage, collected from a Dunkin’ restaurant in the same commercial plaza, showed a maroon Honda CRV circle the area and park out of view of the bank. The driver then walked about 75 yards and into the bank lobby before handing a teller a note. He was quiet and mumbled.

“Don’t want to hurt but armed stay calm (and) quiet,” the note said, according to an affidavit filed by Portland police Detective Jessica Brown in support of probable cause.

Police located the alleged getaway vehicle after the officer doing surveillance in the unrelated drug case ran a Florida license plate on a maroon Honda CRV similar to the vehicle described by the Domino’s employee and visible on the Dunkin’ security footage.

The vehicle’s registration came back to a woman with addresses in North Carolina and Rhode Island.

Police then ran a CARFAX report using the Honda’s unique vehicle information, and learned that it had been serviced recently at a mechanic’s shop in Rockland. A phone number was found on the invoice. The SUV’s owner told Brown she had loaned the vehicle to a friend in Portland named Joseph Evers while she was away briefly in Canada.

She said Evers lived on Lincoln Street, which is close to Forest Avenue and the Westgate Shopping Center. But when they went there, police did not find the SUV, only a truck registered to Evers.

Evers’ friend also told the detective that Evers worked at Handy Boat in Falmouth. When Portland detectives visited the business on Monday, they found both Evers and the Honda CRV.

When they searched Evers, they found specially marked $20 bills that were taken from the Key Bank in Falmouth during the Dec. 10 robbery, according to a report by Falmouth police.