WASHINGTON — A decision to reset the password on an iCloud account associated with one of the San Bernardino attackers did not effectively thwart the investigation into the shooting, FBI officials said in a court filing as part of the Justice Department’s ongoing encryption dispute with Apple.

FBI Director James Comey testified before Congress last week that “there was a mistake” made when the FBI asked San Bernardino County, Calif., which owned the phone, to reset the password for an account tied to Syed Farook, who along with his wife killed 14 people in the Dec. 2 shootings. Authorities were hoping that way to recover at least some of the stored data even while the phone was locked.

In a sworn declaration submitted Thursday, Christopher Pluhar, an FBI agent involved in processing the evidence, said the password reset did not harm the investigation. Farook’s iPhone, which was found powered off, had the iCloud backups turned off for his mail, photos and notes and aren’t believed to be complete, Pluhar said. And even with a full set of backups, the Justice Department said, the government would still have needed to search the phone “in order to leave no stone unturned.”

The statement is aimed at rebutting earlier claims from Apple that said if the FBI had not changed the iCloud password, its engineers could have helped investigators use a known — and therefore trusted — wireless connection to trick the iPhone from automatically backing up to iCloud.

The statement was part of a broader Justice Department filing designed to encourage a federal magistrate to affirm her decision last month to force Apple to help the FBI gain access to Farook’s phone.