In an interview i read last night, Trayvon's dad said Trayvon had been trying to get permission to leave the house all day, and finally came up with the plan to go get skittles because maybe THEN they'd let him leave. (Nothing sinister there, I can see him wanting to stretch his legs and have a private conversation with his girlfriend. This paints a picture of a father who has a stranglehold on him, which is in keeping with his desire to refocus Trayvon after the suspension from school.)
So he came up with this errand to go get Skittles, which he did.
At that point, he never returned and the dad who had been keeping such a hawkish eye on him doesn't do anything or even think anything suspicious.
What's not being said here? How can those two things be true - the Dad was really keeping close tabs on him, and then completely ignored that he went missing and decided maybe he ended up with a cousin at the movies.