12 ELONIS v. UNITED STATES Opinion of the Court nors engaged in sexually explicit conduct. 513 U. S., at 68. We rejected a reading of the statute which would have required only that a defendant knowingly send the prohibited materials, regardless of whether he knew the age of the performers. Id., at 68–69. We held instead that a defendant must also know that those depicted were minors, because that was “the crucial element separating legal innocence from wrongful conduct.” Id., at 73. See also Staples, 511 U. S., at 619 (defendant must know that his weapon had automatic firing capability to be convicted of possession of such a weapon). When interpreting federal criminal statutes that are silent on the required mental state, we read into the statute “only that mens rea which is necessary to separate wrongful conduct from ‘otherwise innocent conduct.’ ” Carter v. United States, 530 U. S. 255, 269 (2000) (quoting X-Citement Video, 513 U. S., at 72). In some cases, a general requirement that a defendant act knowingly is itself an adequate safeguard. For example, in Carter, we considered whether a conviction under 18 U. S. C. §2113(a), for taking “by force and violence” items of value belonging to or in the care of a bank, requires that a defendant have the intent to steal. 530 U. S., at 261. We held that once the Government proves the defendant forcibly took the money, “the concerns underlying the presumption in favor of scienter are fully satisfied, for a forceful taking—even by a defendant who takes under a good-faith claim of right—falls outside the realm of . . . ‘otherwise innocent’ ” conduct. Id., at 269–270. In other instances, however, requiring only that the defendant act knowingly “would fail to protect the innocent actor.” Id., at 269. A statute similar to Section 2113(a) that did not require a forcible taking or the intent to steal “would run the risk of punishing seemingly innocent conduct in the case of a defendant who peaceably takes money believing it to be his.” Ibid. In such a case, the Court explained, the