A man identified as a friend of the Florida neighborhood watch captain who fatally shot an unarmed black teenager says the man would tell the teen's parents he's "very, very sorry" if he could.

Speaking Monday on ABC's "Good Morning America," Joe Oliver said George Zimmerman is someone who thought he was doing the right thing and has now virtually lost his own life.

Both Oliver and Craig Sooner, an attorney speaking for Zimmerman, said there is other evidence that hasn't come out that shows Zimmerman was acting in self-defense when he shot and killed 17-year-old Trayvon Martin in February.

The shooting in a gated community near Orlando has sparked widespread outrage, with many calling for Zimmerman's arrest.

Zimmerman's father is white and his mother is Hispanic.