CHESTERFIELD, MO (KTVI) – Don’t keep your garage door openers in your car overnight and don’t leave your garage open. That’s the message police want folks to remember after a series of overnight home invasions in St. Charles.

Recently, thieves have broken into cars, taken the garage door openers, and used them to open garages and enter the homes.

It’s not just St. Charles taking this type of home invasion seriously.  For years, Chesterfield police have taken a proactive approach to making sure garage doors stay shut at night.

It’s a simple, typed letter, left daily in mailboxes across Chesterfield. You’ll get one if police see your garage door open overnight.

Chesterfield Police Sgt. Dan Dunn says the reason is simple: “A thief is going to take that house that’s got the open garage door over the one that’s shut.”

On average, 76 notes are handed out each month.

Chesterfield resident Katie McManus and her husband have received quite a few. She says, “I thought he had locked up and I was sleeping, thinking that we were all safe and sound, and in fact, we weren’t. But I think it’s a good idea, it’s good to know they’re out driving around, keeping everybody safe.”

Police also want criminals to know they’re actively patrolling neighborhoods. Dunn explains, “If you have somebody that’s looking to commit a crime, if they see police cars in the area, they’re gonna try to pick someplace else hopefully.”

Chesterfield resident Lori Loynd says those letters are a good reminder, and learned that the hard way.

Loynd says, “We left the garage door open and somebody entered, opened the door to the house.  Luckily I saw them open the door and they shut it really quick, and we weren’t able to find out who that was.  It was a horrible feeling, it really was. Had us shaken up pretty well.”