Police Chief Medaria Arradondo is the third officer to testify against Derek Chauvin, breaking the "blue wall of silence." Chief Arradondo not only called Chauvin's knee on George Floyd's neck a violation of policy and training, but also a violation of department ethics and values. Jamie Yuccas reports. Each weekday morning, "CBS This Morning" co-hosts Gayle King, Anthony Mason and Tony Dokoupil deliver two hours of original reporting, breaking news and top-level newsmaker interviews in an engaging and informative format that challenges the norm in network morning news programs. Subscribe to “CBS This Morning” on YouTube: https://www.youtube.com/user/CBSThisMorning Watch CBSN live: http://cbsn.ws/1PlLpZ7c​ Download the CBS News app: http://cbsn.ws/1Xb1WC8​ Follow "CBS This Morning" on Instagram: http://bit.ly/1Q7NGnY Like "CBS This Morning" on Facebook: http://on.fb.me/1LhtdvI Follow "CBS This Morning" on Twitter: http://bit.ly/1Xj5W3p Subscribe to our newsletter: http://cbsn.ws/1RqHw7T​ Try Paramount+ free: https://bit.ly/2OiW1kZ For video licensing inquiries, contact: [email protected]