The FBI, which teamed up with Boston Police this past spring to investigate a series of armed store robberies across the city, on Tuesday arrested a man they say held up a convenience store on Blue Hill Avenue in Dorchester just 35 minutes after he held up a convenience store in Brockton.

Fernando Bost, 32, was arrested on federal charges of interference with commerce by threats or violence and being a felon in possession of a firearm and ammunition for holdups in Dorchester and Brockton in March. In April, police in Springfield arrested him and found a loaded handgun in his hoodie pocket, according to an affidavit by an FBI agent on the case.

He is the third person to be arrested on federal charges in less than a month for Boston armed robberies this spring, including another man charged with holding up a Fields Corner Dunkin' Donuts at the point of two knives.

According to the affidavit in Bost's case, unsealed in federal court:

:Based on a review of surveillance and police reports, on March 29, 2023, at approximately 11:05 P.M., a male entered the RJ Smoke and Convenience Store located at 844 Blue Hill Avenue in Dorchester, Massachusetts, and approached the victim cashier and brandished a black colored handgun. The male walked behind the counter while assuming a crouching position and aimed the handgun directly at the victim cashier. While at gunpoint, the male issued commands to the victim cashier. The victim cashier took a kneeling position behind the cash register. The victim cashier opened the cash register and raised his hands up. The male took cash out of the tray in the register while forcing the victim cashier to kneel with his face towards the floor and his hands on the ground. The male took approximately $700 to $800 in U.S. cash. The male fled the store onto Blue Hill Avenue towards Vesta Road."

Investigators reviewed surveillance video from the area, which helped them narrow their search to a late-model maroon Kia Sorento - and a guy who wore a hoodie and black sweatpants emblazoned with the phrase "Ice Cream."

That was the same kind of car and outfit worn by a guy who'd held up a store in Brockton just 35 minutes earlier, according to the affdavit.

On March 31, the affidavit continues, officers on patrol in Codman Square noticed a Kia Sorento matching the description sent out in a BOLO heading in the other direction. They couldn't turn around in traffic to follow it, but were able to get a license-plate number, which, according to the affidavit, led investigators to a Hyde Park woman who had rented out her Sorento on a service called Getaround, which lets people put their cars up for use by others.

The investigators then subpoenaed rental and use records from Getaround, which led them to a Roslindale woman who'd rented the car - and which placed the car just down the block from the Blue Hill Avenue and Brockton stores shortly before they were robbed.

Boston detectives knew the Roslindale woman "from previous interactions, several of which were due to her association with an individual named Fernando Bost " - possibly of a romantic nature.

"Upon review of BOST's criminal record, investigators noted that it included several charges for armed and unarmed robbery along with three outstanding warrants issued out of three different courts (West Roxbury Division of the Boston Municipal Court, Framingham District Court, and Hampden Superior Court). The outstanding warrants include charges for armed robbery, assault with a dangerous weapon, breaking and entering daytime for felony, receiving stolen property, and shoplifting.

"BOST was also sentenced in 2012 out of Hampden Superior Court for four and a half to five and a half years for armed robbery and again in 2017 out of Hampden Superior Court to six years to six years plus one day for armed robbery."

On April 5, investigators contacted Springfield Police about Bost, who had ties to that area - and the Sorento had registered a visit to the city on March 31 - and asked that officers look for him, adding he might now be in an Infinit, since his Roslindale girlfriend had rented the Sorento while her normal wheels were in the shop.

"BOST was removed from the vehicle and placed in handcuffs. During a search incident to arrest, officers retrieved a black firearm located in the front sweatshirt pocket worn by BOST. The firearm was later identified as a Glock 43x, nine-millimeter handgun with serial number BPLS383. The firearm was loaded with a high-capacity magazine containing ten rounds of nine-millimeter ammunition with one round in the chamber. The handgun recovered from BOST’s person resembles the handgun observed in the RJ Store robbery surveillance."

The next day, the affidavit continues, FBI agents and Boston detectives interviewed Bost, whom they say admitted holding up RJ's.

"BOST confessed to investigators he robbed the convenience store on Blue Hill Avenue. During the interview he told investigators he walked down the street and did the 'boys' s*** and went right back like it was nothing'. BOST did not know the name of the store but knew exactly where the store was located. BOST stated he was ;in and out' of the store."

He said his girlfriend drove him, but didn't know he was going to rob the store. He told her specifically to park on Blue Hill Avenue "because he wanted her to think he was visiting his baby mother's house (who resides on Blue Hill Avenue)."

When investigators told Bost they'd want his phone to check its GPS data, he "stated looking at his phone for GPS is pointless, BOST turns his phone off and does not bring his phone with him when he does robberies."