(CBS NEWS) SANFORD, Fla. - There's a family inside a quiet subdivision in Sanford, Florida that is both grieving and frustrated. Their unarmed teenage son was killed here - and they can't understand why the gunman is still free when he has admitted pulling the trigger.
"He was lying in this area," Tracy Martin tells CBS News, pointing to the patch of grass where his teenage son was shot dead 10 days ago.
Trayvon "Trey" Martin, 17, lived in Miami. He loved horses, and dreamed of becoming a pilot.
The high school junior was visiting relatives last month when he was shot and killed inside this gated subdivision of town homes.
"He meant the world to me. He meant the world to his mother," says the young man's father. He and his wife were to give a news conference later Thursday to discuss the case.
Around 7:00 p.m. on February 26, Martin was walking back from a 7-Eleven a half-mile away where he had bought an iced tea and a bag of Skittles.
At 7:17 p.m., 26 year-old George Zimmerman, a neighborhood watch member, called police to report a suspicious person inside the gated community. A dispatcher told Zimmerman police were on the way and to let them handle it.
Just two minutes later, six neighbors dialed 911 to report a fight - and then a gunshot.
Trey Martin, shot once in the chest, lay dead on this walkway just 70 yards from the home where he was staying. He was unarmed.
"He was up here to relax. He wasn't up here to return home in a body bag. That's the part that tears me up," says his father. "And for me not to be able to save his life is hard."
Sanford Police have questioned Zimmerman, but not charged him. He had a legal permit to carry his concealed weapon, a 9-mm handgun.
For now, he's a free man who maintains he acted in self-defense.
Zimmerman has admitted to shooting Martin, according to police.
Sanford Police chief Bill Lee confirms that Zimmerman was armed and Martin was not.
Lee says no one saw how or why the fight began, and that police are trying to establish whether Zimmerman did act in self-defense.
Tracy Martin says if anyone was trying to defend himself, it was his son.
"Why would he attack this guy?" asks the father. "He don't know this guy. What was he going to do -- attack him with a pack of skittles?"
Lee says he understands Martin's frustration.
"It's their 17-year-old son. I have a 16-year-old son and I couldn't imagine experiencing what they're experiencing," Lee said.
George Zimmerman is a college student majoring in criminal justice. Neighbors and police say he has lived somewhere else since the shooting. CBS News could not reach him or find any trace of him online.
Tracy Martin wants Zimmerman to face a jury for killing Trey.
"My kid went to the morgue and this guy went home to sleep in his bed," Martin said. "There's no justice in that."
To see Mark Strassmann's full report, click on the video in the player above.