In a letter to state and local law enforcement partners, the FBI says it will help the authorities break into locked mobile devices when it is allowed by law and policy.

In the two-paragraph letter, which was obtained by Reuters and Buzzfeed news, the government agency said it understands the challenges local authorities face when it comes to the monitoring and investigation of suspects who use encrypted mobile devices.

"As has been our longstanding policy, the FBI will of course consider any tool that might be helpful to our partners," the FBI said. "Please know that we will continue to do everything we can to help you consistent with our legal and policy constraints."

The document doesn’t specifically say that the FBI will use the same method to unlock encrypted devices for state and local law enforcement as it did for the San Bernardino iPhone. It does, however, say that it “will of course consider any tool that might be helpful to our partners.”

The DoJ dropped its legal case against Apple after a third-party, widely believed to be Israeli mobile forensics firm Cellebrite, stepped forward to help crack Syed Rizwan Farook’s locked iPhone. Only a few days after saying it no longer required the Cupertino company’s assistance, the FBI agreed to help unlock two Apple devices in a separate Arkansas murder case.

There are several obstacles when it comes to applying the FBI/Cellebrite technique to other Apple devices. It was designed for an iPhone 5c running iOS 9, meaning it wouldn’t work on newer models/operating systems. There's also the chance that Apple could release a patch that fixes the vulnerability to stop the method from being used.

According to the Washington Post, the DoJ and FBI are still debating whether or not the new technique should be used to help crack other iPhones. As the organizations have classified the tool, using it in state and criminal prosecutions that require disclosure of evidence to defendants would pose a problem.

The government’s case against Apple may have gone away, for now, but the privacy versus security battle will continue.

Here’s the full letter:

Since recovering an iPhone from one of the San Bernardino shooters on December 3, 2015, the FBI sought methods to gain access to the data stored on it. As the FBI continued to conduct its own research, and as a result of the worldwide publicity and attention generated by the litigation with Apple, others outside the U.S. government continued to contact the U.S. government offering avenues of possible research. In mid-March, an outside party demonstrated to the FBI a possible method for unlocking the iPhone. That method for unlocking that specific iPhone proved successful.

We know that the absence of lawful, critical investigative tools due to the "Going Dark" problem is a substantial state and local law enforcement challenge that you face daily. As has been our longstanding policy, the FBI will of course consider any tool that might be helpful to our partners. Please know that we will continue to do everything we can to help you consistent with our legal and policy constraints. You have our commitment that we will maintain an open dialogue with you. We are in this together.

Kerry Sleeper
Assistant Director
Office of Partner Engagement
FBI