[新闻背景]The Florida man accused of killing an unarmed African-American teenager is expected to be free soon on $150,000 bail.  George Zimmerman is charged with second degree murder in connection with the shooting death of 17-year-old Trayvon Martin in February.  Zimmerman claims self-defense. 

George Zimmerman appeared in court not only to seek his release as he awaits trail - he used the opportunity to apologize to the dead boy's parents who attended the proceedings.

"I wanted to say I am sorry for the loss of your son," he said.  "I did not know how old he was, but I thought he was a little bit younger than I was, and I did not know if he was armed or not."

The fact that Trayvon Martin was not armed, and that Zimmerman was, is partly why the case has attracted so much attention. Florida has what's called a Stand Your Ground law that allows people to use deadly force if they feel their lives are in danger.  

Zimmerman says he shot Martin in self-defense after Martin attacked him.  Zimmerman's father testified by telephone about how his son looked after the confrontation.

"His face was swollen quite a bit," said Robert Zimmerman. "He had a protective cover over his nose, his lip was swollen and cut."

Prosecutors portray Zimmerman as the aggressor who confronted Martin as he walked back to his father's home from a nearby convenience store.  Prosecutors contend that Zimmerman has a history of violence.

Zimmerman's wife Shellie contradicted that in her testimony by phone.

Prosecutor: "You would tell the court that he is not a violent person?"

Shellie Zimmerman: "Absolutely, he is not a violent person or a threat to the community."

AP

The parents of Trayvon Martin, Sybrina Fulton, left, and Tracy Martin, sit in the courtroom, April 20, 2012, during a bond hearing for George Zimmerman in Sanford, Florida.

Also hanging over this case is the controversial subject of racial profiling.  Martin's family and supporters argue that Zimmerman, a white Hispanic, neighborhood watch volunteer, stopped Martin because he was black.

That has led to numerous protests across the country. Part of this outcry came after police initially allowed Zimmerman to go free.  And the volatility of the case was on the mind of Zimmerman's attorney after the hearing.

"It is an enormously high profile case and there is a lot of anger - or let's say a lot of high emotions - that exist," said defense attorney Mark O'Mara. "I don't want that to spill over on to the family or my client's safety."

The hearing ended with the court setting conditions for Zimmerman's release.

"I am going to grant the motion and set bond in the amount of $150,000 with the following conditions - electronic monitoring GPS," said Florida judge Kenneth Lester.

The judge also ruled that Zimmerman must check in with authorities every three days.  He is scheduled to return to court in May to be formally charged.