Baby was dropped off with baby's daddy. I think Leah had to run an errand at Walmart, I think to pick up medicine, maybe she dropped the baby off because she was sleepy & cranky & she didn't want to take her to Walmart, it was late, 9pm, would've been baby's bedtime? Or maybe it was baby daddy weekend so she dropped her off after going to the graduation. I don't think the trip to her work was in the original plan stated when she headed to Walmart or dropped off the baby, maybe something later on reminded her she had forgotten it, after she left Walmart Leah phoned her dad & said she was done at Walmart but had forgotten something at work so she was going to run by there & then she'd be by to drop off/bring the medication to her dad. Idk if she lived alone, with her dad or with baby's daddy.
This is just how I understood things when I read thru everything.
She was either meeting someone at the work place or she really did need to pick something up (what that something is who knows?), maybe she saw something she wasn't supposed to or just became a victim for no reason other than someone is sick in the head.
All just moo