SANFORD, Fla. -

After opening statements in the George Zimmerman trial, prosecutors called their first witness --  a Seminole County teenager -- to the stand Monday afternoon.

Chad Joseph, 15, was the last one to spend time with Trayvon Martin before Zimmerman killed him Feb. 26, 2012.

We were "watching TV and playing a game," Chad said.

The two teens played Play Station 3 and watched TV before Trayvon left walking to a nearby 7-Eleven to buy him candy. Chad wanted Skittles. And he stayed home because he wanted to continue playing his PS3 video game.

On Monday morning, Chad wore a white polo shirt that was buttoned up all the way up. He also wore black baggy jeans. Trayvon's dad is his mom's boyfriend, the boy said. That is how he met Trayvon.

Chad told attorneys he learned about the fatal shooting after school.