Nearly two months after he admittedly shot and killed 17-year-old Trayvon Martin, George Zimmerman unexpectedly apologized to Martin's parents at a bail hearing in Sanford, Fla. on Friday. "I wanted to say I am sorry for the loss of your son," Zimmerman, 28, said in a "meek" voice. "I did not know how old he was. I thought he was a little bit younger than I am. I did not know if he was armed or not." (Watch the video below.) Zimmerman faces a charge of second-degree murder, but claims that he acted in self-defense. Judge Kenneth Lester granted him a $150,000 bail, though Zimmerman is still not expected to leave jail for several days. Here, five takeaways from the day's events:

1. Martin's parents are outraged
Martin's parents are quite angry that Zimmerman would "give a self-serving apology to help him get a bond," said Ben Crump, the Martin family attorney. Hold on, says Zimmerman attorney Mark O'Mara. Zimmerman wanted to apologize, and while "it should have been done in a private setting... that [opportunity] wasn't afforded to him." (On Thursday, Martin's parents rejected Zimmerman's request for a meeting.)

2. Zimmerman will be tracked
The judge granted bail on the condition that Zimmerman would wear a monitoring bracelet on his ankle. Zimmerman was ordered not to contact Martin's family, and to abide by a 7 p.m. to 6 a.m. curfew each night. Lester is still weighing whether to allow Zimmerman to leave Florida. Zimmerman's lawyers say he's not safe in the Sunshine State, having reportedly received multiple death threats. Zimmerman is still in jail, and his lawyer says it could take some days for his family to come up with the money to post the $150,000 bond.

3. Prosecutors say he has a history of violence
In seeking to deny him bail, prosecutors grilled Zimmerman's wife, Shellie Zimmerman, about her husband's past arrest for assaulting an undercover police officer, and another incident in which an injunction was filed against him by a former girlfriend who claimed Zimmerman had hit her. Shellie Zimmerman, testifying by telephone, insisted that Zimmerman had merely acted in self-defense. "He's absolutely not a violent person or a threat to the community," she testified.

4. Lawyers are previewing their trial strategies
O'Mara went after Dale Gilbreath, an investigator for the state attorney's office, when he took his turn on the stand. O'Mara aggressively questioned Gilbreath about an affidavit he had drawn up, in which he said Zimmerman "confronted" Martin. Gilbreath conceded that he did not know who started the fight. Also, when prosecutors asked Gilbreath if there was any evidence to suggest that Zimmerman had made untrue statements to the police, Gilbreath replied, "Yes."

5. Meanwhile, a new photo of a bloodied Zimmerman emerges
ABC News published a photograph showing the back of Zimmerman's head covered in blood mere minutes after Trayvon died. "The photo could give credence to Zimmerman's claim that Martin had bashed his head against the concrete as Zimmerman fought for his life," says ABC. Investigators had already seen the photo, and Crump said it proved nothing. "How bad could it have been if they didn't take him to the hospital [and] didn't stitch him up," he said. "The special prosecutor has seen all the evidence and still believes George Zimmerman murdered Trayvon Martin."

Sources: ABC News, CBS News, The GuardianThe Los Angeles TimesThe New York Times, Tampa Bay Times