What is the test for a jury to determine whether a defendant committed a first degree murder by deliberate and premeditation?

Murder is first degree when deliberate and premeditated. If the elements of either deliberation or premeditation are absent, the murder is in the second degree. (Pen. Code, 189.) When the evidence shows only that the defendant killed the victim but nothing more, malice may be inferred but the killing is second degree murder and not first degree murder. (People v. Lines (1975) 13 Cal.3d 500, 506.) Defendant asserts no evidence of what occurred immediately before the killing allowed the jury to find deliberation and premeditation.