A senior FBI official says she doesn’t think hiring third parties to help the FBI hack into locked iPhones should be the solution.

Amy Hess, executive assistant director of the FBI’s science and technology branch, was asked at a congressional hearing about the Justice Department’s decision to use an unidentified outside contractor to break into a phone used by one of the San Bernardino, California attackers. That branch oversees the use of surveillance technologies.

She says those kinds of decisions are made case-by-case, but that relying outside entities to exploit vulnerabilities isn’t the solution.

She said the FBI relied on a third party because the work requires highly specialized resources that the agency doesn’t have readily available on its own.