In an abrupt about-face, the wireless industry said Tuesday that smartphones will offer optional, reversible "kill switches" starting next year as a way to deter thieves.

The antitheft tool will let users remotely erase their personal data and render phones inoperable if they are lost or stolen, according to CTIA, a wireless-industry trade group. If a phone is recovered, the owner will be able to return it to working condition and restore the wiped data.

A who's who of smartphone makers and wireless carriers said they would voluntarily offer the new technology for phones manufactured after July 2015. They include Apple, AT&T, Google, HTC, Motorola, Microsoft, Nokia, Samsung, Sprint, T-Mobile and Verizon, among others.

An epidemic of smartphone thefts has prompted lawmakers nationwide to propose bills that would mandate kill switches.

A pre-emptive move

"The industry is making a move so they're not forced to do so by the government," said technology analyst Jeff Kagan. "It's better for them to solve the problem than wait for the government to come in with a nuclear bomb. From what I've read, this is the kind of approach we need."

However, some legislators and law enforcement concerned about rampant thefts of mobile devices said the new "voluntary commitment" is inadequate because it requires many users to "opt in." CTIA said the tool would either be downloadable or come preinstalled.

"For the solution to have an impact on the street where the crimes occur, it must be ubiquitous," said state Sen. Mark Leno, D-San Francisco, author of a bill that would require smartphones to come with a kill switch by next year. "It should come enabled when you purchase your phone and the retailer activates it. That is fundamental to communicating to potential perpetrators that their stealing these phones will be a worthless venture."

Leno said he will move forward with his bill, SB962, which is slated to be heard on the Senate floor next week. It would make the technology "opt-out," meaning consumers would have to act to disable it.

At the national level, bills mandating kill switches in smartphones were introduced this year in both the House of Representatives and Senate.

Some lawmakers - including state senators in Oregon, Minnesota, Illinois and Rhode Island quoted in the CTIA statement - praised the new solution for protecting consumers.

"We got the kill-switch technology we wanted to protect Illinois consumers," Illinois state Sen. Toi Hutchinson said in the release.

No. 1 property crime

Smartphone thefts have grown increasingly violent as the devices have risen in value, commanding several hundred dollars each on the black market. More than 1.6 million Americans had smartphones, tablets or other devices stolen in 2012, according to Consumer Reports. The Federal Communications Commission said mobile-device theft is the No. 1 property crime in America.

The industry has struggled with a response. Some companies already voluntarily offer technology to help thwart thieves, while others said it was technically unfeasible, prohibitively expensive or would open the door for hackers to maliciously disable phones. Just this month, Leno said, industry representatives testified they couldn't offer the type of solution that they now are proposing.

Some critics pointed out that the industry reaps billions of dollars by selling insurance for smartphone loss or theft. They also make money selling replacement phones after thefts. If kill switches were standard, most consumers would buy cheaper insurance, or none at all, and theft would presumably decline.

A survey of 1,200 smartphone users by William Duckworth, a statistics professor at Creighton University, found that 99 percent thought carriers should allow all consumers to disable stolen phones, and 93 percent said that shouldn't cost them extra.

SF District Attorney Responds

So far this year, said San Francisco District Attorney George Gascón, two-thirds of the robberies in the city involved a cell phone or tablet, up from half the crimes in 2012.

"I commend the industry for taking this step after fighting it for nearly two years," he said in an interview.

However, Gascón and New York Attorney General Eric Schneiderman echoed Leno's concerns about the new measure.

"It falls short of what is needed to effectively end the epidemic of smartphone theft," they wrote in a joint statement. "Today's announcement is an important acknowledgment by the smartphone industry that technology to deter theft is not only feasible, but also practical. Accordingly, our work must continue until the standard is that these solutions are enabled by default."

©2014 the San Francisco Chronicle