The two videos feature the family of Marcus Mason, who was gunned down in 2007. His murder remains unsolved.
The mayor told hundreds of cheering supporters Tuesday night that he would take aim at long-standing challenges in the growing city.
Nevertheless, the challengers hope to capitalize on some of the discontent in Denver surrounding development, affordable housing, transportation and other issues.
Two other candidates are running in the May election, but neither is considered a serious challenge to Mayor Michael Hancock.
"We have a community that is completely fed up with being mistreated, with being brutalized," said panelist Lisa Calderon.
Denver Mayor Michael Hancock responds to the string of recent videos involving law enforcement officers and allegations of abuse of power.
New cultural plan spearheaded by Denver Arts & Venues is the result of months of consultations with thousands of Denver residents.