Denver Mayor Mike Johnston was in Washington, D.C. on Wednesday for a date with Congress – one that he likely would have been subpoenaed for had he not gone willingly. Johnston testified as House Republicans investigated "sanctuary cities." While there is no legal definition of a sanctuary city, Denver does limit local cooperation with federal immigration agents to cases where they have a warrant or are trying to pick up a violent criminal. https://www.9news.com/article/news/politics/national-politics/denver-mayor-testify-congress-sanctuary-city-hearing/73-1906b7a5-bd49-48a1-82fb-45f16d7d31b0 More local videos here: https://youtube.com/@9news Subscribe to NEXT: https://youtube.com/@Nexton9NEWS Stay connected: 9NEWS Website: http://www.9news.com/ Facebook: https://www.facebook.com/ilike9news Twitter: https://twitter.com/9NEWS Instagram: https://www.instagram.com/9newsdenver/ Download the 9NEWS App: https://www.9news.com/appredirect/ Sign up for the 9NEWSLETTER: https://www.9news.com/email 9NEWS (KUSA) is located in Denver, Colorado.