Hey! Thank you for playing the Cold Case! It was very helpful and insightful seeing you play the game. Love the Shatner voice that you gave Kowalski and your Moss impression - we're huge IT crowd fans.
You were very close! You and the chat were on the right track with using the moteltimesheet to determine when the victim arrived at school - you HAD the correct time when you did the math of the travel time. Take another crack at the bookstore time. The bookstore receipt indicates time that the left, but what about the time when they FIRST got to the bookstore... Take a closer gander at the torn bookstore flyer. Bigger hint below...
The flyer states that it's only a short walk from Roosevelt Elementary. If you know what time the victim left school AND you know that they went to the bookstore next then you should be able to deduce when they STOPPED BY the bookstore.