Can a man who killed a fetus carried by his estranged wife be prosecuted for murder?

In 1970, section 187, subdivision (a), provided: "Murder is the unlawful killing of a human being, with malice aforethought." In Keeler v. Superior Court (1970) 2 Cal.3d 619, 87 Cal.Rptr. 481, 470 P.2d 617, a majority of the court held that a man who had killed a fetus carried by his estranged wife could not be prosecuted for murder because the [7 Cal.4th 803] Legislature (consistent with the common law view) probably intended the phrase "human being" to mean a person who had been born alive.