DENVER -- Five months after Colorado became the first state to allow recreational marijuana sales, the battle over legalization is still raging.
Law enforcement officers in Colorado and neighboring states, emergency room doctors and legalization opponents increasingly are highlighting a series of recent problems as cautionary lessons for other states flirting with loosening marijuana laws.
There is the Denver man who, hours after buying a package of marijuana-infused Karma Kandy from one of Colorado's new recreational marijuana shops, began raving about the end of the world and then pulled a handgun from the family safe and killed his wife, the authorities say. Some hospital officials say they are treating growing numbers of children and adults sickened by potent doses of edible marijuana. Sheriffs in neighboring states complain about stoned drivers streaming out of Colorado and through their towns.
"I think, by any measure, the experience of Colorado has not been a good one unless you're in the marijuana business," said Kevin A. Sabet, executive director of Smart Approaches to Marijuana, which opposes legalization. "We've seen lives damaged...We've seen marijuana getting into the hands of kids."
Despite such anecdotes, there is scant hard data. Because of the lag in reporting many health statistics, it may take years to know legal marijuana's effect -- if any -- on teenage drug use, school expulsions or the number of fatal car crashes.
It was only in January, for example, that the Colorado State Patrol began tracking the number of people pulled over for driving while stoned. Since then, marijuana-impaired drivers have made up about 1.5 percent of all citations for driving under the influence of drugs or alcohol.
Proponents of legalization argue that the critics are cherry-picking anecdotes to tarnish a young industry that has been flourishing under intense scrutiny.
The vast majority of the state's medical and recreational marijuana stores are living up to stringent state rules, they say. The stores have sold marijuana to hundreds of thousands of customers without incident. The industry has generated $12.6 million in taxes and fees so far, though the revenues have not matched some early projections.
Marijuana supporters note that violent crimes in Denver -- where the bulk of Colorado's pot retailers are -- are down so far this year. The number of robberies from January through April fell by 4.8 percent from the same time in 2013, and assaults were down by 3.7 percent. Overall, crime in Denver is down by about 10 percent, though it is impossible to say whether changes to marijuana laws played any role in that decline.
"Every major institution said this would be horrible and lead to violence and blood in the streets," said Brian Vicente, one of the authors of Amendment 64, which legalized marijuana in Colorado. "None of that's happened. The sky did not fall."
The argument is being waged with fervor because both sides say Colorado's successes and failures with regulating marijuana will shape perceptions of legalization for voters considering similar measures in other states and for leery federal law enforcement officials. After the 2012 legalization votes in Colorado and Washington state -- where recreational sales are expected to begin this summer -- Justice Department officials gave the states a cautious green light.
But they warned that they might intervene if marijuana ended up fueling violence or drug trafficking, or flowing across state lines or into the hands of children.