Authorities are investigating a rash of recent crimes that has erupted in the Duluth area and Carlton County.

Suspects were arrested in connection with those cases.

However, police say their biggest concern isn't so much robberies, but home invasions.

Police say there have been at least five home invasions since September.

Even though this is a larger number than usual, police are saying that each one of the victims was targeted for a specific reason by the suspect.

"It's significant we had a number of them where it jumps out at me and I do want to clarify again that these are not random events," said Sgt. Bob Shene with the Duluth Police Department.

Police are urging Northlanders to take safety precautions to protect themselves from a burglary or home invasion.

Police say it is important to be careful where you put a hide–a–key.
Don't put it in a place where it can be easily found.

Write down the serial numbers of all the expensive items in your home.
This will help police find them if they ever get stolen.

And if you are going to be out of town, put automatic timers on your lights and have your neighbors collect your mail.

"The idea is to make it look like the house is being lived in and give people a heads up when you are coming and going so that they know. That way if I know you're not going to be back for five days and I see someone at your house, that's an issue," said Shene.

Due to the recent crime activity, security system companies are seeing a rise in sales.

"The last year sales have been increasing substantially over the past year but specifically within the last 2–3 months there has been a notable increase in sales," said Mike Jubie with Great Lakes Alarm & Security Products Inc.

Many people have security systems installed in their home as an extra safety measure, but it is important to recognize that these devices can only do so much.

"Security systems are a huge deterrent, but the homeowner needs to take precautions on themselves. Watch your home; take a look around through the neighborhood. Watch for strange cars in the neighborhood," said Jubie.

If you do choose to get a security system, it is important to make sure the company has a key holder.

This way if the alarm does go off, then the police have a way to get into the home to make sure everything is alright.