The case involving a court order demanding Apple helps the FBI unlock the iPhone linked to one of the San Bernardino killers is unlikely to be a trailblazer for setting a legal precedent in future cases, FBI director James Comey told a congressional panel on 25 February. The complex and evolving nature of mobile phone software will limit how broadly the case can be applied, Comey said during a US House of Representatives Intelligence Committee hearing examining worldwide threats.

While the case will be instructive for other courts, broader policy questions about reasonable law enforcement access to encrypted data will likely need to be resolved by Congress and others, Comey said.

The FBI is seeking Apples help in accessing a county-owned iPhone 5C used by Syed Rizwan Farook, who along with his wife went on a shooting rampage in December that killed 14 and wounded 22. Last week, it obtained a court order from a California magistrate asking Apple to comply.

Apple has said the request amounts to asking a company to hack its own device, would undermine digital security more broadly and would set a troubling precedent for how companies must comply with law enforcement. The San Bernardino case is not about us trying to send a message, Comey said.

Apple CEO Tim Cook told ABC News on 24 February the company is willing to take the case to the US Supreme Court if necessary.