JACKSONVILLE, Fla. -

The Jacksonville Sheriff's Office is investigating a string of thefts involving dropboxes at apartment complexes throughout the city.

Police said the thieves are gaining access to the dropboxes that renters use to drop their rent payments in and are cashing money orders. About 30 cases have been reported over the last four months, resulting in losses of thousands of dollars.

Police said they have reached out to many apartment complexes in Jacksonville asking them to stop using the dropboxes at this time.

"We want to let renters know that this type of activity is occurring and we ask them not to use dropboxes to prevent themselves from becoming a victim," JSO spokeswoman Melissa Bujeda said in a news release. "If you are a renter, physically hand your payment to apartment office personnel or use an online payment system that many complexes have in place."

Additionally, police said money orders are not easily traced when cashed. But the rent money still has to go through, so for some victims, that could mean having to pay twice.

"People don't realize they've been victimized until one, two, maybe three weeks later when they get a notice that their rent wasn't paid at the complex on time," Bujeda said. "They know they put it in the dropbox, and at that time, JSO starts backtracking to try to find out what occurred."

What's happening doesn't sit well with renters like Cori McCullough.

"It's kind of scary because you work so hard to pay your rent and then thieves are going in and just taking it," McCullough said. "I'd like more complexes to do the online banking versus the dropboxes if this is going on."

Anyone who has any information about who is responsible for these thefts is asked to contact the Jacksonville Sheriff's Office at 904-630-0500 or email JSOCrimeTips@jaxsheriff.org. To remain anonymous and receive a possible reward up to $3,000, contact Crime Stoppers at 866-845-TIPS.