Comey’s comments this week about how the FBI hacked into the phone of one of the killers in the San Bernardino shooting were the first since law enforcement officials postponed an impending court hearing with Apple in late March. At the time, the Justice Department only said that it had received help from an outside source and would no longer try to force Apple to give investigators access to the phone.

Speaking to audience members at Kenyon College in Ohio, Comey said that he trusted the unnamed source and that “their motivations align with ours,” according to CNN Money.

While Comey didn’t say how the tool worked, he said that the method was “perishable” because of its applicability to the iPhone 5c, which is becoming less common as Apple continues to create newer models. So far, the Justice Department has not revealed the tool to Apple, though it is considering doing so, according to Politico.

Law enforcement officials’ discovery of a tool to access the shooter’s phone quickly wound down the growing public battle between Apple and the government, but it didn’t solve the disagreement at the core of the fight: whether Apple should be required to grant the government access to customers’ personal information.