WASHINGTON (AP) — The Justice Department is firing back at Apple for refusing to help unlock a phone used by one of the gunmen in the San Bernardino attack.

In a new motion Friday, federal prosecutors say the company has chosen to repudiate a judge's order instead of following it.

The department also says Apple designs its products to allow technology — "rather than the law" — to control access to critical data.

Prosecutors also make clear that Apple would be allowed to retain possession of the phone and technology.

The motion offers a sharply worded response to a message that Apple's chief executive officer, Tim Cook, said in a message to Apple customers this week.

It represents a further escalation in a public relations battle that the two sides are waging.