(dissenting).
I do not see how we can avoid holding it was error not to give the requested manslaughter instruction. When we announced the requirement that instructions must be given on second degee murder and manslaughter in all cases where the pleadings and evidence warrant submission of conventional first degee murder, it amounted to a declaration by this court that whenever there was evidence sufficient to submit conventional first degee murder there is also evidence sufficient to submit second degee murder and manslaughter and it is the function of the jury to decide whether the defendant acted with premeditation and malice: conventional first degree murder *285involves an intentional killing with deliberation and premeditation; but a jury may disbelieve the evidence as to deliberation but believe it as to premeditation, thus finding second degree murder; or the jury may disbelieve the evidence both as to deliberation and premeditation, which under Sec. 559.070, RSMo 1969, still leaves manslaughter, assuming the homicide is not justifiable or excusable.
If we were correct in what we did, then the fact the present case was tried before March 1, 1975, is immaterial, because if first degree murder includes all that is necessary to prove a case of second degree murder or of manslaughter, depending on what the jury chooses to believe or disbelieve, that proposition does not depend on a particular date — it comes about because of what goes to make up first degree conventional murder. That did not change on March 1, 1975 or suddenly include something on that date it had never contained before. So there inevitably were facts present in the case before us on which the jury could have returned a verdict of manslaughter, it being conceded that the evidence “amply supported a charge of first degree murder.” That being so, the requested manslaughter instruction should have been given and for the failure to do so the judgment should be reversed and the cause remanded.
If this is not so, then by insisting that in all conventional first degree murder cases there must also be instructions on conventional second degree murder and manslaughter, we would be helping convict defendants on second degree murder or manslaughter whether there was any evidence to warrant such submissions or not. I know that I for one had no such intention when I agreed to the requirement above mentioned. Therefore, I respectfully dissent.