U.S. Postal Service investigators are looking into a wave of mail thefts that have occurred in Vallejo and American Canyon over the past two and a half months.
The Postal Service’s law enforcement branch says about 300 mailboxes in the two towns have been cleaned out since Feb. 1. Thieves have targeted 23 mailbox clusters, which each serve anywhere from 12 to 18 households.
Jeff Fitch, a spokesman for the U.S. Postal Inspection Service, said Thursday that two postal workers were robbed in the area earlier this year, and agents are investigating whether thieves could be using their stolen master keys to open the mailbox clusters.

It’s not a trivial crime, Fitch said, with theft of the U.S. mail carrying a possible penalty of up to five years in federal prison and a $250,000 fine.
“The mere possession of that counterfeit key is up to 10 years in federal prison, so that’s how seriously we take these things,” Fitch said.