BELFAST – Police in two counties are making progress in their investigation of four recent armed robberies in central Maine, but charges have been filed in just two of the cases, Waldo County’s chief deputy said Thursday.

Already in jail after last week’s armed robbery of the Unity Pharmacy, Sean D. Kivlin, 29, of Unity on Tuesday was charged in connection with the Nov. 21 armed robbery of the Fairfield Rite Aid pharmacy.

In addition, police continue to investigate whether Kivlin is connected to the Dec. 21 armed robbery of the Pittsfield Pharmacy and the Jan. 6 armed robbery of the Unity branch of Bangor Savings Bank.

Investigators from Maine State Police and police and sheriff’s departments in Waldo and Somerset counties are working jointly on the cases.

“The investigation is ongoing. We’re making progress,” Waldo County Chief Deputy Bob Keating said Thursday.

Keating said Fairfield police arrested Kivlin at the Waldo County Jail on Tuesday after a DNA sample retrieved from the getaway vehicle in the Fairfield robbery matched a sample obtained from Kivlin.

Keating said Kivlin apparently had left mucus or saliva in the vehicle after Fairfield police chased him from the robbery scene and sprayed him with pepper spray as he was leaving in a vehicle. The getaway vehicle was recovered from a vacant farm in the Waldo County town of Montville a week after the Fairfield robbery.

Kivlin appeared Tuesday in 5th District Court in Belfast on charges stemming from last week’s armed robbery of the Unity Pharmacy. Kivlin was arrested Jan. 21 at gunpoint by state police Sgt. Thomas Ballard after his car was immobilized when it ran over a spike mat on Route 131 in Appleton. Bail was set at $100,000 cash.

Keating said bail in the Fairfield case was set at $180,000 cash.

The Fairfield robbery on Nov. 21 was followed up by the Dec. 21 robbery of the Pittsfield Pharmacy and last week’s robbery in Unity, also on the 21st. All of the robberies were carried out by a lone male who was masked and armed with a gun and knife.

Police were aware of the pattern of three successive robberies on the 21st of the month and had increased their patrols the day of the Unity robbery.

Unity pharmacist Shane Savage also was aware of the robbery dates and had filled a few prescription drug bottles with M&M candies in case the armed robber made an attempt at his store. When the robber entered the store at noon wearing mittens with a scarf around his head, carrying a butcher knife in one hand and a gun in the other, he left with the bottles of candy.

Besides apparently tricking the robber into thinking he had left with narcotic drugs, Savage also followed the getaway car from the store and gave police a description over his cell phone. Though Savage lost sight of the fleeing vehicle, state police detective Scott Bryant saw the car on Route 3 and chased the vehicle into Appleton where Ballard was waiting with the spike mat. The mat flattened two tires, and Kivlin was arrested without incident.