No, but it does help prosecutors establish the intent element of a second degree murder charge imo. If he is convicted of second degree murder, a judge will likely consider his laying in wait (as well as the pre-planning involved, of course) as aggravating factors for sentencing. Second degree murder carries a minimum sentence of 15-25 years and a maximum of life, so a judge will consider aggravating and mitigating factors to determine what they believe to be an appropriate sentence within this range. These factors are also significant to the prosecution in determining what, if any, plea deal to offer.