What is the standard for making a mistake-of-identity arrest?

Plaintiffs offer only one controlling case that they believe meets this standard, United States v. Delgadillo-Velasquez , 856 F.2d 1292 (9th Cir. 1988), but we reject it as too dissimilar on its facts. In that case, officers had an "untested tip" about a known drug dealer, a printout of his physical description, a twenty-year-old photograph of the fugitive, and his apartment address. Id. at 1294, 1296. The officers conducted surveillance of the apartment building over two days and observed an apparent drug transaction made outside the building by a Latin male whose appearance did not match the photograph. Id. at 1294. The officers then arrested that Latin male, but he ultimately was not the suspect they were looking for. We concluded that the officers lacked probable cause to make the arrest, and we rejected the mistake-of-identity defense because "they had no reason to believe" the arrestee was their suspect. Id. at 1297.