Is an attorney's performance deficient for failing to present mitigation evidence at a sentencing hearing in a capital case?

In Evans v. Lewis, 855 F.2d 631 (9th Cir.1988), we also held an attorney's performance deficient for failure to present mitigating evidence at the sentencing hearing in a capital case. But there, "counsel presented no evidence of mitigation" at all, even though the relevant death penalty statute required the sentence of death where at least one aggravating factor and no mitigating factors were presented. Id. at 637 (emphasis in original). Counsel's failure to present any mitigating evidence in that case could not be construed as a trial tactic. Id.