I wanted to create this guide in case anyone was having as much trouble getting this achievement done as I did. The place I found best to farm this achievement is during the Brainfreezer district boss battle. Throughout the battle there are plenty of enemies that come down to attack you that make it easy to stack up your combo. Make sure to get the rapid attacks in by spamming X when your opponents are stunned. Also, I found that it helped to use a character with super speed like Dash to help get attacks in quicker and also hop between enemies quicker.
If you have already finished the Brainfreezer battle, but have not finished the rest of the Crime Waves, see the spoiler below for what to do.
*** Spoiler - click to reveal ***If you have finished the Brainfreezer battle and still have more Crime Waves to complete, finish the rest of the Crime Waves. After the last Crime Wave is completed, you can go to the New Umbra Prison and release any of the villains you have captured, allowing you to replay that Crime Wave, and thus repeat the boss battle.
For you visual learners, here is a guide I found that shows how to get this achievement as well as the Senior Citizen's Arrest achievement. I did not create this video, all rights go to Clarky1005 on YouTube.