A Dorchester man was arrested Monday on charges he and some pals were using a Norfolk Street auto-body garage to sell cocaine and counterfeit Percocet pills made out of fentanyl - which authorities say may have helped cause a fatal overdose last year in a local man man struggling with addiction.

Rodolfo Peralta Salcedo, 38, was arrested today on a federal charge of conspiracy to distribute and posses with intention to distribute fentanyl as part of a ring that allegedly sold drugs to customers in both Boston and New York according to documents unsealed today in US District Court in Boston. Additional arrests could come, including that of the apparent ring leader, now identified in court records only as "Luis."

In an affidavit, a Massachusetts state trooper working on a DEA task force says it was the dead man's phone that helped lead investigators to Peralta's operation and to several drug buys in Codman Square.

In December, about six months after the man died, his parents let task-force members go through his phone, which had numbers for possible drug merchants, including "LUIS Blues," "LUIS Buddy" and "Luissss" and gave them his shaving kit, which contained five blue pills marked as Percocet that might actually have been pressed fentanyl - tests to identify what the pills are made of are still pending.

On Jan. 10, the affidavit continues, the man's wife told investigators both she and her late husband had been buying what they thought was Percocet and cocaine since 2013, mainly from a man they knew as Luis, but sometimes from his courier, whom they knew as "Luis's buddy."

And then, on Feb. 21, the trooper writes, Luis sent a text to what he thought was his still living customer.

"On February 21, 2022, the 9219 Phone (the deceased’s phone) received an incoming text message sent from LUIS’s 3553 Phone, which read, 'This is my new number (LUIS).' On February 25, 2022, the 9219 phone received an incoming text message from the 3553 Phone that read, 'What up bro.'

"On March 1, 2022, the 9219 Phone received two more text messages from the 3553 Phone, which read, 'My time from now on and I’ve got some new stuff. 9am/11pm. It’s Luis' and 'All day every day.' The second text was followed with a smiley face and thumbs up emojis. The deceased’s widow received the same two messages on March 1 from the 3553 Phone."

An undercover agent pretended to be the dead man and started a text conversation that resulted in a "friend" contacting Luis and inquiring about buying drugs - which led to the "friend" agreeing to pay $175 for five of the "blues" - the alleged Percocet pills. Luis also tried to drum up business in New York, saying he could supply drugs down there to any friends of the friends.

In March and April, undercover agents posing as friends of the dead man made three purchases of "blues" - possibly fentanyl pressed into Percocet-like pills - on Norfolk Street in Codman Square. The first purchase was from a man later identified as "Luis's buddy" or Peralta, the affidavit states:

"PERALTA had a respirator mask around his neck. PERALTA handed the UC a piece of paper that contained five blue pills. In return, the UC [undercover agent] gave PERALTA $175. At 2:18 p.m., PERALTA walked away from the UC vehicle toward the area [down Norfolk]. A surveillance officer observed PERALTA enter the fenced in area of the Target Location [the auto-body garage]. At 2:28 p.m., an investigator saw PERALTA on the phone outside of the front gate to the Target Location still with a respirator around his neck. The blue pills PERALTA sold the UC had the "M/30" markings and appeared to be counterfeit oxycodone pills. Based on my training and experience and knowledge of this investigation, I believe they likely contain fentanyl. A field test yielded an inconclusive result, and the pills were sent to the DEA laboratory for testing."

The location was about a block away from the operation's apparent home base - Ally’s Inner City Auto Body &amp Sales at 41 Norfolk St., where Peralta worked. For the second and third purchases, agents who had that site under surveillance watched Peralta leave there and walk the short distance down Norfolk where Luis had the "friends" park for their transactions.

On May 9, an agent texted Luis about making a larger purchase, of 100 pills, but tried to bargain Luis down on the price. Luis said he could do $28 a pill, but no lower and the "friend" agreed - and agreed to meet on Hopestill Street, a couple blocks from the auto-body shop.

But this time, Peralta didn't show, in fact, agents on a stakeout there watched him get in a car at the garage and drove away:

"Based on my training and experience, I believe LUIS did not deliver the drugs to the UC because either he or someone who worked for him believed the UC was working with law enforcement. I further believe PERALTA left the Target Location because whoever alerted LUIS also alerted PERALTA about the presence of law enforcement."

Fortunately for the agents, though, they had cultivated a source, a person who had bought drugs from Peralta for years, before quitting the habit, but who then started buying from him again last year after relapsing. Shortly after 5:50 p.m. on June 30, the affidavit states, that person purchased a number of pills from Peralta a block or so away from the auto-body shop, using money supplied by the DEA. Agents watched as Peralta walked from the shop to the source's car, sold him pills, then, after a quick stop at a local barber shop, returned to the garage and closed it up for the night.

"[E]ach time a drug order has been placed during the course of this investigation, whether it was a last minute order or an advance order, LUIS has directed the buyer to the vicinity of the Target Location [the garage] and PERALTA has either come on foot from the area of the Target Location or directly from the Target Location to deliver the drugs. As detailed above, the SOI told investigators that over the course of the last six months, he has purchased fentanyl pills from PERALTA several times a week in the vicinity of the Target Location."