The alleged thieves spotted last month stealing mail across San Francisco with what is believed to be a USPS master key remain on the loose, and officials are still investigating just how, exactly, these criminals managed to acquire the key in the first place. What's more, residents in the 94109 zip code — which is believed to be specifically at risk — remain vulnerable as changing all the impacted locks is a massive, expensive, and time-consuming task.

The story first came to light in August when KTVU reported that a pair of suspected thieves had been captured on surveillance video stealing mail from a Van Ness Avenue building. What made the situation so unnerving was that unlike your average package thief, these two had what appeared to be a USPS master key — allowing them to buzz themselves in to multi-unit apartment buildings and open all the mailboxes inside.

Buildings in Japantown, Cow Hollow, and Fort Mason were reported to have been hit by the duo.

We reached out to US Postal Inspector Jeff Fitch of the San Francisco division for an update on the case, and he assured us that investigators are working hard in conjunction with the San Francisco Police Department to find these two. "Our goal is to identify the individuals and arrest them," he told SFist by phone. "These things do take some time."

Fitch assured us that he knows residents in the 94109 zip code are frustrated that the thieving pair haven't been caught, and that he and his office are taking this case extremely seriously. "Right now we're actively investigating this and attempting to catch up with these individuals," he explained before adding that the mere possession of the key is punishable by up to ten years in federal prison.

When pressed as to just how, exactly, the key fell into wrong hands, Fitch wouldn't say — noting that how the key was acquired, and whether it is genuine or counterfeit, is part of the investigation.

But as time drags on, those living in the 94109 zip code are still at risk. SFist pressed Fitch on whether or not locks were being changed — a process that KTVU reports could cost at least $200,000 — but he would only say that "the Postmaster is assessing that right now" and that "if we were changing the locks we wouldn't announce it either — we try not to telegraph what we're doing security wise."

This is not the first time a lost, stolen, or counterfeit USPS master key has made the news in recent years. The Napa Valley Register reports that one was "lost" in 2011, and The Eastersider reported last year that thieves had likely scored a master key in LA's Silverlake neighborhood.

This fits a pattern of increased mail theft in California identified by Fitch, noting that his agency has seen other instances of master key theft and counterfeiting in the Golden State before. When asked whether or not he believed the suspected criminals pictured above were still actively out there stealing mail, Fitch declined to say. "I don't want to speculate on what they may or may not be up to, but they appear to be very comfortable with what they're doing — while they're drinking coffee," he explained, referencing surveillance video showing the thieves casually carrying coffee cups as they went about their illegal business.

There is a $10,000 reward for tips leading to the arrest and conviction of whoever is behind the recent spate of mail thefts. Anyone with knowledge can call Fitch's office at 877-876-2455, and residents of the 94109 zip code who may have been impacted should email [email protected] directly.

Previously: Thieves Got A USPS Master Key And Are Pilfering Mail Across The City