Police are constantly searching for instances of illegal drug possession. They imagine themselves in high-level busts leading to the incarceration of global traffickers. When that eludes them, they are content to lock up average users carrying even tiny amounts.
Among the tools at their disposal are drug-sniffing dogs. Whether they may use one depends on the conditions.
Using drug-sniffing dogs during a vehicle stop
Law enforcement officials may legally pull over drivers for a host of infractions. Examples include speeding, an expired license or going through a red light. As long as the justification for the stop falls within the law, an officer may circle the vehicle with a K9. No warrant is necessary, yet the check cannot be inordinately long.
Using drug-sniffing dogs on the street
Police lack the right to search pedestrians without legitimate suspicion of criminal conduct. Under the right conditions, bags and purses are subject to testing from a trained nose. On occasion, a dog may deliver a positive alert. Officials do not have to gain permission to rummage through personal belongings if it is incidental to an arrest.
Using drug-sniffing dogs at a private home
Warrants are usually necessary for narcotics hounds to inspect residences. Besides interiors, this includes porches and front yards. The exception is when probable cause exists. The qualifications for probable cause are highly narrow, making it tough to justify.
Laws exist to protect civilians as well as help law enforcement capture criminals. When police violate these rules, drug charges should be subject to dismissal.