Large numbers of §1983 complaints assert Fourth Amendment "malicious prosecutions" claims. The gravamen of the claim is that the plaintiff was criminally prosecuted without probable cause. Although the claim challenges the initiation of criminal legal process, a prosecutor's decision to prosecute is shielded by absolute prosecutorial immunity. Imbler v. Pachtman, 424 U.S. 409 (1976). The claim would thus have to be asserted against a law enforcement officer, such as an arresting officer, who played a meaningful role in bringing about the criminal prosecution. See Hartman v. Moore, 547 U.S. 250, 261-62 (2005).