Justice for Victims of Confidential Informant Crime Act of 2017 This bill amends the federal judicial code to extend to three years and six months the period within which a tort claim against the United States must be presented in writing to a federal agency when the claim arises out of a government employee's conduct with respect to the criminal misconduct of a government informant. (Current law bars all tort claims against the United States that are not presented within two years after the claim accrues.) The extension applies retroactively to any such claim that: (1) accrued on or after May 1, 1981; and (2) in the case of a claim accrued before the date of enactment of this bill, is presented within one year after such date. The government is prohibited from asserting a defense or a bar, based on the doctrine of res judicata or collateral estoppel, to a claim that accrued before enactment of this bill and to which this bill applies.