TOMPKINS COUNTY, N.Y. (WETM) — The Tompkins County Sheriff’s Office is warning residents of an increase in check fraud happening in the county.

According to a release sent out by the sheriff’s office, they’ve seen an increase in check fraud occurring throughout the county over the past month.

They say that checks are being stolen from residential buildings in the county, specifically out of mailboxes with red flags up, indicating outgoing mail.

Police say that criminals are doing “Check Washing” where they take a common over-the-counter chemical found in many stores and removed the pen ink from the check. From there the person is able to rewrite a new name and money amount onto the check.

Another form of fraud that police have noticed is the changing of numbers/letters on the checks.

Police say that someone committing the fraud will take the check and change an amount from $2,500 to read $3,500, by simply adding a line under the “2” to make it a “3.”

What are ways to prevent check fraud?

The sheriff’s office is recommending residents drop off outgoing checks directly to their local Post Office for delivery, instead of putting them in the mailbox.

Another tip is for residents to purchase a “Fraud Prevention” pen. These pens are designed for the ink to absorb into the check rather than roll ink on top of the check. The type of ink used by these pens can’t be removed by “check washing” techniques.

A final suggestion is for check writers to use bold and blocky letters when writing the checks, and use the majority of the space on the line. Doing this technique makes it more difficult for the check to be altered.