Paraphrasing from the attached article - Roberts worked the night shift prior to this shooting, and made his milk truck runs. He ended his shift at 3 a.m. Mon. morning. He took his children to the bus stop at 8:45 and returned to his house.
Roberts was a lifelong area resident and it is known that he probably had contact with some of his victims families through his job collecting raw milk from farms.
Psychologists have speculated that Robert's acted deliberately by going to the school to get even with the community by targeting their most vulnerable targets, their children.
From the presser:
They indicated they are still in process of outreach to find out if the numerous offers of assistance will be accepted.