Some bad guys are determined. Usually, we see this when in movies when the master thieves stop at nothing to pull of their heist. No security system is too good to stop them because they simply won’t quit.

Occasionally, the determined bad guy isn’t quite up to the Thomas Crown level.

A man was arrested after he fought with an officer, pulled two guns on him, then tried unsuccessfully to steal the cop’s gun on the South Side, authorities said.

The officer approached a group of men in the 8800 block of South Wallace Street in Gresham around 1:40 p.m. Sunday, police said.

Jamie Harrison, 33, ran off and the officer chased him down and the two began struggling, police said.  Harrison pulled a revolver from his pants and held it to the officer’s chest. The officer overpowered Harrison and grabbed the gun — only for Harrison to pull out a second one, police said.

When the officer wrestled that one away, Harrison tried to pull the officer’s gun from his holster. Additional officers arrived and Harrison was arrested.

The officer was taken to the hospital where his condition was stabilized.

Harrison was treated and released, probably straight into general population at the jail. He’s now charged with four felonies, including attempted murder and disarming a police officer. He was also charged with an armed habitual violator.

This kind of behavior isn’t the norm, to be sure. Most criminals tend to go a fair bit more quietly than Harrison allegedly did. Most terrorists seem to go more quietly than Harrison did, for that matter.

Luckily, it looks like the officer involved will be fine, which is fortunate since Harrison seemed really, really determined not to go back to prison.

However, it does indicate something we as private citizens need to bear in mind.

Criminals can be determined. There’s no reason to believe that pepper spray, rape whistles, or even a low-end stun gun will do anything to stop an attacker who truly means to cause harm to you. A police officer reportedly disarmed Harrison twice before having to use his weapon retention training. Do you really think a squirt of pepper spray would have made a difference?

Arm yourself. Arm those you love if they’re old enough. Learn how to use that gun and share that knowledge with those you love. If, God forbid, you’re faced with a determined attacker like this, do not stop until they do. Period.

This was an armed police officer, and that did nothing.

It’s up to you to make sure you’re not easy prey for someone like this who intends to cause harm to you and yours. You have to be willing to match their determination, though you have an advantage. It’s your life that’s at risk. They can defuse the situation by walking away. You don’t get to do that.

In this case, I’m glad all worked out well for everyone involved except maybe Harrison. If convicted, he’ll be off the streets for a long time, which is a win for the people of Chicago.