Apple has submitted a legal brief opposing the US government's attempt to force the company to unlock an encrypted iPhone belonging to one of the San Bernardino shooters, one day before the filing deadline.
The US Federal Bureau of Investigation is seeking Apple's help to access shooter Syed Rizwan Farook's iPhone by disabling some of its passcode protections.
Apple has pushed back, arguing that such a move would set a dangerous precedent and threaten customer security.
In a copy of the brief provided by the company, Apple argued that the government's request is "unprecedented" and violates the company's First Amendment rights.
"This case is not a case about one isolated iPhone," Apple said in the filing on Thursday, reiterating previous comments.
Earlier in the day FBI Director James Comey told a congressional panel that court approval of the FBI's request was "unlikely to be a trailblazer" for setting a legal precedent.
While the case "will be instructive for other courts", larger policy questions about reasonable law enforcement access to encrypted data will likely need to be resolved by congress and others, Comey said.
