(CNN) - Denver Mayor Michael Hancock opposed legalized recreational marijuana use and sales in his city, worried the city would become known as the marijuana capital, and concerned about the impact on kids.

Recreational use of marijuana has been legal in Colorado for more than a month.

"That's now water under the bridge. No, I did not support it when it went for a vote before the people, but at the end of the day, it's now legal in Colorado and Denver. And my job ... is to make sure it works according to the people's plan," said Hancock.



Medical marijuana has been legal in Colorado for more than ten years, long enough to study related crime.

"Where we have those medical marijuana dispensaries, we have seen an uptick in crime – robberies, and intrusions," said Hancock.

But as for recreational marijuana use and crime, the city remains in "uncharted territory, we don't know how it impacts our neighborhoods," said Hancock.

The mayor said he knows of a few robberies and attempted robberies at retail marijuana stores, "but nothing that has raised a major red flag."

Texas Governor Rick Perry spoke at Davos this week, saying he supports policies that move to decriminalize marijuana, but not to legalize it – perhaps a reflection of Republicans softening on marijuana laws.

"People don't want to see us continue to incarcerate people behind what they consider petty offenses of possession," said Hancock.

Unfortunately too many people, particularly young men of color, "have had their lives ruined, their futures impacted because they've been arrested with small arrests of marijuana," said Hancock.

For more of our interview with Mayor Michael Hancock, check out the video above.