Elk Grove’s post office at Williamson Drive was burglarized late last month, the U.S. Postal Inspection Service confirmed on Aug. 2.

The office staff discovered that mail was stolen during the morning of July 26. The unknown thief or thieves remain at large.

Jeff Fitch, a spokesperson’s for the U.S. Postal Inspection Service, said that investigators are still trying to determine how much mail was stolen. They are also investigating to see which residences were affected before sending notifications to the victims.

“At this point, we don’t have a piece count yet on the amount of mail that was taken,” Fitch said.

The spokesperson said that the burglarized occurred at the post office’s building. There are currently no descriptions of the suspect or suspects. Fitch said that postal investigators are in contact with the Elk Grove police.

The U.S. Postal Inspection Service is offering a $10,000 reward for information that leads to the arrest and conviction of the burglar. Fitch said that mail theft is a federal offense and could lead to a punishment of five years in prison and a $150,000 fine.

Elk Grove residents who review their bank or credit card statements and notice purchases they did not make are encouraged to contact the U.S. Postal Inspection Service’s 24-hour hotline at (877) 876-2455. They can also contact the Elk Grove police at (916) 714-5115.