The Waukesha Christmas Parade on November 21 was a horrific tragedy. A man driving a SUV plowed through the parade killing six innocent people and injured more than 60 others. But it never should have happened. We need to start asking questions about why our criminal justice system is releasing violent criminals.

After talking with Waukesha officials and attending the interfaith vigil, I understand the pain in that community. While we don't want outside influences making the situation worse, we cannot downplay the horror of this intentional act. There was a murderer who committed these crimes (not a car like CNN's headline suggests). Catch and release is not only a problem on the southern border, but also in our criminal justice system.

Today I led a moment of silence for the parade victims in the U.S. Senate. WATCH: