After a Boston ABC television news affiliate called the state's locksmith trade association pretending to be locked out, the locksmith picked the lock in less than two minutes and charged $90.

When the same television news crew randomly picked a locksmith from the phone directory, the locksmith quickly gave up picking the deadbolt and drilled the lock, offering to replace it for $175, according to a televised sting on locksmiths.

Complaints about locksmiths recently prompted California's Department of Consumer Affairs, working with the San Francisco District Attorney's Office, to conduct a sting to weed out unlicensed locksmiths. Three of five locksmiths were cited for operating without a license after they responded to the bogus request to change locks.

Representatives of the same locksmith company that riled California officials were fined thousands of dollars after Chicago's Department of Consumer Services charged them with fraudulent acts, deceptive practices and operating without a license.

The three incidents are among dozens of recent news accounts, including televised investigative reports and law enforcement stings the Association Locksmiths of America (ALOA) has compiled as part of a campaign to warn consumers about the emergence of a troubling trend.

"The consumer is quoted a reasonable price over the phone, but when a person posing as a locksmith finishes the job, the consumer is charged a considerable amount more for unnecessary and sub-standard work," says ALOA's executive director, Charles W. Gibson, Jr.

ALOA has recorded a number of incidents of elderly consumers locked out of their homes and being charged $900 to $1,700 to replace a $12 lock.

The locksmiths featured in the reports typically are not licensed or registered in state or jurisdiction. They are also often part of an out-of-state operation which local authorities are investigating.

ALOA offers a checklist for weeding out locksmiths who aren't operating within the law and we've researched additional tips from the states of California, Florida and Illinois to help you choose a professional locksmith.

• It's a good idea to select a locksmith before you need one. Access to resources for finding a law abiding locksmith are limited when you are locked out of your home. Anxiety and the need for fast help could cloud your judgment.

• Ask family, friends, co-workers and others you trust for referrals. Where applicable, check for licenses (not all states license locksmiths), registered or certified locksmiths, and those affiliated with an association. Verify licenses or certification with the regulatory agency and verify trade group affiliation with the trade group. No designation guarantees the locksmith's work, but they do come with some inherent consumer protections.

• Some legitimate locksmiths will work out of a car for quick jobs, but most will arrive in a service vehicle that is clearly marked.

• Beware of a locksmith who immediately tells you the lock has to be drilled and replaced. An experienced locksmith who has invested in the education and tools of the trade can unlock almost any door.

• The locksmith should ask who you are and record your identifying information, especially when opening a home, business or a car.

• Ask the locksmiths for a detailed price for a lockout. Don't pay for service in advance and always ask that "defective" parts be returned to you.

• Beware of companies that don't advertise a street address, answer the phone with a generic phrase, such as "Locksmith service" and those that don't clearly identify their company name.

• Also beware of offers of multiple discounts, emergency service promotions, claims of lowest prices, "No. 1" self-ratings and other puffery.