IPHONE

Now that the FBI has managed to crack its way into an iPhone used by one of the San Bernardino, Calif., shooters, the floodgates may be opening   despite the agency's previous statement that its legal battle with Apple was about just one phone.

The FBI has agreed to help local law enforcement unlock an iPhone and iPod connected to an Arkansas murder case, the Associated Pressreported. And FBI officials pledged to "consider any tool that might be helpful" to local law enforcement partners in an advisory sent to departments that had inquired about the technique used on the San Bernardino iPhone, according to Buzzfeed News.

Although the advisory stopped short of explicitly saying the agency would use the undisclosed method deployed on the San Bernardino phone, it referred to the high-profile case. The FBI has been debating whether the technique, which is classified, should be used to help with state and local criminal investigations

If  that technique is used to help, there may be limitations, because the FBI -- which has declined to identify who helped the agency unlock the San Bernardino phone -- would likely be unwilling to testify about the method. Otherwise, it might be forced to reveal how the hacking tool works.

"I would very much think that a defendant would be on strong legal footing in wanting to know how the method works -- although that disclosure might happen not publicly, but behind closed doors and be subject to various protective orders," said Alex Abdo, a staff attorney at the American Civil Liberties Union. That means that local law enforcement would probably need to avoid using evidence gained by the technique during prosecutions.

During the legal stand-off in San Bernardino, Apple argued that the FBI's demand that the company create a tool to bypass some of Apple's own security features would ultimately endanger all iPhones. The FBI responded that the case was about only one phone.

"Even if 'criminals, terrorists, and hackers' somehow infiltrated Apple and stole the software necessary to unlock [San Bernardino shooter Syed Rizwan] Farook’s iPhone, the only thing that software could be used to do is unlock Farook’s iPhone," investigators wrote in one court filing.

But FBI Director James Comey also acknowledged in a congressional hearing that the agency would potentially use a favorable ruling to pursue similar unlocking requests in other cases.

Still, it's uncertain just how helpful the mysterious technique will be to local law enforcement, even if the FBI is in a sharing mood: The San Bernardino case involved an iPhone 5C, a slightly older model of phone -- and the devices that police want help with may have different hardware and software combinations that aren't vulnerable to the method.