Richard Nieva/CNET

A California bill that mandates smartphones sold in the state come preloaded with antitheft software cleared its first legislative hurdle on Thursday.

SB962, introduced by state Sen. Mark Leno and sponsored by San Francisco District Attorney George Gascon, asks that device makers including Apple and Samsung put so-called "kill-switch" technology on every smartphone and have the switch automatically turned on when people buy a phone. A kill switch lets users lock the phone if it is stolen, making it inoperable.

The bill, which was initially shot down by senators on April 24 -- now has to make it through the California Assembly. Eventually it will need to be approved by California Gov. Jerry Brown, as well.

The bill is in response to a rising tide in smartphone theft. According to a study released by the mobile security firm Lookout on Wednesday, one in 10 smartphone owners in the US has had a phone stolen. In 2013, 3.1 million Americans were the victims of smartphone theft -- nearly twice as many as the year before, according to Consumer Reports. On Gascon's home turf of San Francisco, 67 percent of robberies in the first few months of 2014 have involved mobile devices.

Currently, the tally is 26 "yes" votes to 8 "no" votes -- with 21 votes needed to pass the 40 member Senate. When the bill was brought up for a vote in late April, it fell short two votes of the minimum. The bill applies only to smartphones, and not other mobile devices such as tablets, manufactured after July 1, 2015.

The Senate approval is a legislative victory in a nascent push by lawmakers to curb smartphone theft. On the federal level, a similar bill, the Smartphone Theft Prevention Act, was introduced in the US Congress in February. That bill is still in committee. On Tuesday, London Breed, a San Francisco supervisor, announced she would write kill-switch legislation at the city level. Across the country, New York Attorney General Eric Schneiderman, who has worked closely with Gascon, has been leading the charge in New York.

Apple and Microsoft, which had publicly opposed the bill, both backed off their stances this week. "I applaud Apple and Microsoft for breaking rank and dropping their opposition to SB 962, ignoring the false claim that this technology is unworkable," said Leno, in a statement.

Apple and Microsoft declined to comment.

Gascon lauded the vote. "We're one step closer to ending the violence and victimization that far too many people have been subjected to. California truly has an opportunity to lead the way and end this public safety crisis, the potential to end this global epidemic is very real," he said, in a statement.

Much of the debate on the senate floor had to do with who takes the blame if a phone happens to be sold without the kill-switch software, a penalty that would range from $500 to $2,500, according to the bill. As it is written now, the liability falls on the retailers actually selling the phones.

Some senators had concerns over retailers unfairly getting the brunt of the blame. For example, a box of phones meant for another state that didn't carry the software could accidentally be delivered to a California retailer. "It's a big burden on a retailer of anything, that they have complete control over everything they sell," said Sen. Mark Wyland, adding that would be unreasonable for a retailer to turn on every phone to check for a kill switch.

The bill had stalled in the past because of pushback from the wireless carrier industry, which argues that kill-switch software leaves phones vulnerable to hacking.

The telecom industry softened its stance last month when the CTIA, a trade organization that represents the mobile-telecom companies, announced a commitment to make the the antitheft software standard on all phones from participating device makers and carriers -- including Apple, Samsung, Google (which makes the widely used Android mobile operating system), AT&T, Verizon, Sprint, and T-Mobile -- though ultimately the choice to include the software would be voluntary for the companies.

The CTIA continued to oppose the bill on Thursday. "Given the breadth of action the industry has voluntarily taken, it was unnecessary for the California Senate to approve SB962, which would mandate a specific form of anti-theft functionality," Jamie Hastings, the CTIA's vice president, external and state affairs, said in a statement.

The No. 1 and No. 2 largest smartphone makers in the world, Samsung and Apple, already offer antitheft software to users of their devices. In September, Apple added "activation lock," a feature that makes it harder for someone to use a stolen iPhone. The program requires a user's Apple ID and password before they can turn off the phone's location tracking or reactivate a locked phone. Last month, Samsung, maker of the popular Galaxy smartphone line, launched "reactivation lock," which prevents a locked phone from being made operable again, even through a factory reset.

Under the CTIA's voluntary commitment program, the kill-switch features would come automatically turned off by default. The bill's supporters argue that requiring a customer to turn on the antitheft feature defeats its purpose, since the intent of the law is to send a message to would-be thieves that stealing an inoperable phone would be useless. Leno said the wireless industry's resistance has to do with money, specifically losing business from insurance partners.

When the bill was presented two weeks ago, a common refrain from opposing senators was that it would be bad for business in California. Republican leader Robert Huff implied over-mandating would drive tech companies -- which have been a definite boon to California's economy -- to move out of the state.

Huff's office defended his position, but when CNET contacted the 17 senators who voted down the bill in April, 14 of them either did not respond or said they were unavailable when asked for specifics about the business harm. Sen. Jean Fuller said the companies would implement the technology in their own ways without regulation, and Sen. Anthony Canella said his issues weren't with business factors, but that the issue should be decided on a federal level.