What is the test for determining whether an asserted federal right was clearly established at the time of alleged violation?

In this case, the district court did not identify the specific right allegedly violated or indicate whether the right was clearly established at the time of the alleged violation. Instead, the court proceeded directly to the third inquiry: whether a reasonable official, under the circumstances, could have believed that her conduct was lawful. Because the question of "[w]hether an asserted federal right was clearly established at a particular time . . . presents a question of law," we can determine such in the first instance. Elder v. Holloway, 510 U.S. 510, 516 (1994); see also Mendoza, 27 F.3d at 1360.