PROVIDENCE, R.I. (WPRI) — When a group of men abducted a U.S. Postal Service worker in 2021, police allege they had been surveilling the mail carrier because cocaine had gone missing from a package delivered from Puerto Rico.

Federal prosecutors alleged the offenders abducted the Pawtucket mail carrier at gunpoint, forced him into a vehicle and drove him to his home, which they planned to search. Police eventually arrested five men and accused them of a broader cocaine conspiracy that involved trafficking illegal drugs through the mail.

Federal data obtained by Target 12 through a public-records request shows cases involving illegal drugs being sent through the mail have risen sharply in recent years, growing especially fast during the pandemic in Rhode Island.

The U.S. Postal Inspection Service -- which is the oldest law enforcement agency in the country -- reports there were 15 arrests tied to prohibited narcotic cases in 2019. The number grew to 25 arrests in 2020 before spiking to 40 in 2021, then falling slightly to 32 in 2022.

"What we are focused on is fentanyl, synthetic opioids, cocaine and methamphetamine -- those are the things that are having the largest impact," David Reardon, the agency's assistant inspector in charge, told Target 12 during a recent interview in Boston.

As highlighted by the Pawtucket case, which is still making its way through the federal court system, illegal drugs sent through the mail can represent a significant threat to the public, along with mail carriers.

U.S. Postal Service spokesperson Steve Doherty denied requests to interview local mail carriers for this report, saying, "we do not have a carrier who can speak on this subject."

"Anything related to drugs is the domain of the inspection service," he added.

Doherty then refused to respond to multiple emails, calls and texts asking whether local carriers could be interviewed to talk broadly about their jobs and whether they have changed in recent years.

Postal workers deliver about 162 million pieces of mail each day across the country, and federal data shows robberies have soared from 64 in 2019 to more than 400 in 2022. The inspection service estimates there have been more than 2,000 crimes against letter carriers since 2020.

"Any attack on a Postal Service employee is something we take very seriously," Reardon said. "And we have sadly run the entire gamut from assaults on employees to, in some cases, homicides."

Locally, the inspection service partners in tasks forces with East Providence, Pawtucket, Providence and the R.I. State Police. And illegal drugs in the mail is a recurring aspect of local drug cases, including last year when a Bristol man was charged for receiving illegal narcotics through the mail.

A Pawtucket man was recently sentenced to seven years in prison for his role in a national drug trafficking operation, where the drugs were being hidden in Halloween decorations and toys. Police said the man hid 485 fentanyl pills in a toy truck that he planned to mail, according to court records.

"They're out there in society and we're trying to make sure that they don't get into the mail stream," Reardon said. "If they do get in, we're getting them removed and we're going after the people responsible for them."

Reardon said local collaboration is important when trying to discern where drugs are coming from and where they end up. The inspection service often serves as the national partner and will work with agencies in different parts of the country, as illegal mail often originates from other states or other countries.

"One of the benefits of being a federal agency is that for us it's a phone call to California or wherever it might be to try and identify what we can about who might be mailing that package," Reardon said.

Mail is also protected by federal law, meaning law enforcement cannot simply open packages they believe are suspicious without first convincing a federal judge to sign off on a federal search warrant.

Reardon said he encourages everybody to take notice of what's getting mailed into their neighborhoods when possible. One potential red flag, he said, is when people receive packages with no return address, as criminals sometimes send drugs to other people's homes and try to grab them while they're on the porch or steps.

"The thing that I think is helpful is if the public pays attention," he said.