Published: Aug 12, 2014 10:38 AM EDT

COLLIER COUNTY, Fla.- The Collier County Sheriff's Office is investigating several reports of check washing, wherein a criminal erases the ink on a check with chemicals and then rewrites the name of the payee and the amount of the check to his or her benefit.

In the cases currently being investigated, the checks were stolen at night from mailboxes in industrial parks in North Naples and East Naples. However, detectives say it’s a crime that can happen anywhere.

“The number one tip is to never leave checks in an unsecured mailbox overnight,” said CCSO Financial Crimes Bureau Lt. Chad Parker.

Here are more tips to avoid becoming a check-washing victim:

• If possible, take mail to the post office.
• Do not drop off mail at a public mailbox after the last pick up of the day.
• Minimize the number of checks you write by paying bills online on a secure computer. This minimizes the possibility of your checks being stolen through the mailing process.
• When writing out checks, use a gel ink pen (preferably black) so the ink will permeate the fibers of the check.
• Do not leave blank spaces on the payee or amount lines.
• If you still have cancelled checks, shred them.
• Review your bank statements immediately. You have a limited time frame in which to report fraudulent transactions. When fraud is detected, it is necessary to report it within 30 days.
• When possible, have new checks delivered to your bank instead of your home or business..
When ordering new checks, find out what security measures are being used by the manufacturer. These measures may include:
• Chemical voids – this is a counter chemical measure to “washing." This treatment of the check paper causes the word VOID to appear when washing solutions are used.
• Security inks – these inks disappear, fade or stain when exposed to check washing chemicals.