What is the test for a malicious killing committed in imperfect self-defense?

A malicious killing committed in imperfect self-defense is manslaughter, not murder. (People v. Rios (2000) 23 Cal.4th 450, 461.) "Imperfect self-defense obviates malice because that most culpable of mental states 'cannot coexist' with an actual belief that the lethal act was necessary to avoid one's own death or serious injury at the victim's hand. [Citations.]" (Ibid., italics omitted.)

In this case, the jury was properly instructed the prosecution had the burden to prove beyond a reasonable doubt that appellant did not act in imperfect self-defense in killing Villegas. (CALCRIM No. 571.) Appellant argues the record is bereft of substantial evidence the prosecution carried its burden in that regard. In so arguing, he admits the fact he shot Villegas in the head at close range shows he acted with malice. (People v. Valdez (2004) 32 Cal.4th 73, 145.) However, he claims the evidence conclusively established he acted in imperfect self-defense.