He was raised in a racially integrated household and himself has black roots through an Afro-Peruvian great-grandfather - the father of the maternal grandmother who helped raise him.

Zimmerman's maternal grandmother, Cristina, who had lived with the Zimmermans since 1978, worked as a babysitter for years during Zimmerman's childhood. For several years she cared for two African-American girls who ate their meals at the Zimmerman house and went back and forth to school each day with the Zimmerman children.

In 2004, Zimmerman partnered with an African-American friend and opened up an Allstate insurance satellite office, Donnelly said.

"He was so mellow and calm, very helpful and very, very sweet," she said last week. "We didn't really know George at first, but after the break-in we talked to him on a daily basis. People were freaked out. It wasn't just George calling police ... we were calling police at least once a week."

In September, a group of neighbors including Zimmerman approached the homeowners association with their concerns, she said. Zimmerman was asked to head up a new neighborhood watch. He agreed.