The chapter's second* mishpat *verse.
Quick answer
Their own violence is what takes them down, and the verse gives the reason in the second line: they would not do justice.
Read both lines
The verb in the first line is footnoted as literally drag them away, which is more specific than destruction. Violence is pictured as a current that carries off the man who started it, so the agent of his ruin is the thing he did rather than a sentence handed down. Then the second line supplies a motive clause, which couplets in this collection rarely do, and the word is mishpat again. The wicked here are not defined by cruelty in the abstract; they are defined by a refusal, and what they refuse is the thing verse 3 called more acceptable than sacrifice. The chapter is building an argument across its verses rather than listing them.
Related: Proverbs 21:3 · Proverbs 21:15 · Proverbs 1:18–19 · Proverbs 13:23
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.