"However, despite the search warrant and the owner's consent, the FBI has been unable to search the SUBJECT DEVICE because it is 'locked' or secured with a user-determined, numeric passcode," wrote the government in its court documents.
"More to the point, the FBI has been unable to make attempts to determine the passcode because Apple has written, or 'coded,' its operating systems with a user-enabled 'auto-erase function' that would, if enabled, result in the permanent destruction of the required encryption key material after 10 erroneous attempts at the passcode (meaning that after 10 failed attempts at inputting the passcode, the information on the device becomes permanently inaccessible)."
Eileen Decker, U.S. Attorney for the Central District of California, said "We have made a solemn commitment to the victims and their families that we will leave no stone unturned as we gather as much information and evidence as possible. These victims and families deserve nothing less."
"The application filed today in federal court is another step -- a potentially important step -- in the process of learning everything we possibly can about the attack in San Bernardino."
Apple has yet to comment on the matter.