[TKDietz]

"IIRC, 'drug' dogs train exclusiively for drugs, but I could be wrong."

I think you are mostly right. It's not that dogs can't be trained to detect a wide array of substances. The problem is that they can't train one dog to do too much or they tend to not do any of it well. There are some dogs trained for both, but in most cases dogs are trained to do one or the other as that helps ensure the dogs will be accurate. Generally, drug dogs are trained to smell only four or five substances, usually marijuana, meth, cocaine, and heroin. Explosives dogs are trained to smell various types of explosives. The dogs law enforcement use to work the highways are in most cases trained only for drugs. The big asset forfeiture money for law enforcement on the highways is in the drug business so that is where they concentrate their efforts.

[Randy Papadoo]

Not too bad, TKD, except for the reason cops concentrate on drugs.

Forfeiture is an incentive, of course. But the real reason cops work so hard at drug enforcement is because they believe the country, to quote some experts, is "awash in drugs".

Cops don't like to be losing that (or any) battle. Enforcement is their sworn duty! Change the law and see if cops care anymore. But since that isn't happening, they are constantly trying new techniques and approaches to become more effective in the drug war, and that's why I think there's a concentration on drug enforcement by law enforcement. They have to keep trying harder.