In two years of work as an undercover officer with a drug task force, Mike Dillon encountered plenty of drugs. But nothing has surprised him as much as what he has seen in schools lately.

Dillon, who is now a school resource officer with the Mesa County Sheriff's Department, said he is seeing more and younger kids bringing marijuana to schools, in sometimes-surprising quantities.

"When we have middle school kids show up with a half an ounce, that is shocking to me," Dillon said.

The same phenomenon is being reported around Colorado after the 2010 regulation of medical marijuana dispensaries and the 2012 vote to legalize recreational marijuana.