Make no mistake: Marijuana is an addictive gateway drug. It imperils Minnesota's children and threatens public safety in every community. Marijuana use contributes to assaults, homicides, suicide, child abuse, domestic abuse, motor-vehicle crashes and drowning.

The connection between marijuana and violent crime should not be underestimated. The violence related to marijuana isn't a result of the effects on the user but rather stems from the money people can make selling and growing the drug. Violence is part of the trade. By legalizing marijuana-growing operations and drug traffic, we would invite violence into our communities.

California has permitted medical marijuana for more than a decade. The president of the California Police Chief's Association, Jerry Dyer, stated last year, "... it is our observation that it has been destructive to lives and communities. Passage of any form of medical marijuana anywhere in our nation is bad public policy and will cause crime and public safety problems."

In 2006 and 2007, drug and gang task forces in Hennepin County linked marijuana to assaults and homicides. In the Hennepin County Adult Detention Center, 45 percent of males arrested for violent crime test positive for marijuana. Approximately 40 percent of those arrested for property crimes, and 86 percent of those arrested for drug distribution, test positive for marijuana.

We should never lose focus on the immediate connection between guns, gangs, kids and drugs -- and marijuana is frequently the connection. I have been in law enforcement for 25 years and have seen this firsthand. When I was captain of the Criminal Investigations Division with the Minneapolis Police Department, we investigated a case involving a man from out-of-state who tried to buy marijuana for personal use. He unwittingly approached a gang-connected dealer. The man was shot and killed so gang members could keep his money and the marijuana.

Legalizing marijuana for medical use in Minnesota will increase its use and abuse by our children. The Alcohol and Drug Abuse Division of the Minnesota Department of Human Services reported in January 2009 that to protect our kids and succeed in prevention we need to have the same consistent antidrug messages delivered by different messengers: family, schools and community. The department also identified "perceptions of approval of drug using behavior in family, work, school, peer, and community environments" as a key risk factor. If kids are told that marijuana is a safe medication, they will believe it is safe for them to use, too.

Marijuana is especially harmful for kids. Sustained use is detrimental to academic achievement, and it is addictive. In 2007, treatment programs studied 8,178 admissions in Minnesota; nearly half of all those treated for marijuana addiction were under 20. More teenagers are being treated for marijuana abuse than for alcohol plus all other drugs combined. The addiction that will result from legalizing medical marijuana will outweight any benefits.

I have sympathy for people suffering from terminal illnesses or chronic medical conditions. There are other options. The FDA has approved a pill form of marijuana -- marinol. It is considering approval for other types of prescription medication for pain relief. With prescription medication, we can ensure quality standards and dosages, provide warning labels, and manufacture and distribute medications through licensed pharmacies.

I can't agree with a plan to tolerate mixed messages to our youth. I can't agree that law enforcement should be restrained from enforcing drug laws that protect residents and our communities. I oppose legalizing medical marijuana. The American Cancer Society, National Multiple Sclerosis Society, American Academy of Ophthalmology, Minnesota Society of Addictive Medicine, and Minnesota's county attorneys, sheriffs and police chiefs associations all share this view.

Richard W. Stanek is Hennepin County sheriff.