NBC News apologized for the way it edited the 911 conversation between George Zimmerman and a police dispatcher in the Trayvon Martin case.
NBC's "Today" show ran edited audio last week that appeared to reveal Zimmerman saying, "This guy looks like he's up to no good ... he looks black."
But a transcript of the 911 call showed that Zimmerman actually said, "This guy looks like he's up to no good. Or he's on drugs or something. It's raining, and he's just walking around, looking about."
The 911 handler responded, "OK, and this guy -- is he black, white or Hispanic?"
"He looks black," Zimmerman replied.
Zimmerman, a volunteer neighborhood watch leader, admitted shooting and killing 17-year-old Martin in Sanford, Fla., in February but claimed it was in self-defense and justified under the state's Stand Your Ground law. He also claimed Martin attacked him.
Martin was unarmed when he was killed by Zimmerman, who followed him despite being told not to by a 911 dispatcher. The shooting is being investigated.
Martin's death sparked protests across the US, with many angry that no charges were filed against Zimmerman.
The NBC audio was aired Mar. 27. Critics claimed the edited version suggested Zimmerman targeted Martin because he was black.
The network launched an investigation after criticism in other media. Fox News presented a "before" and "after" version of the call last week.
A statement from NBC said Tuesday, "During our investigation, it became evident that there was an error made in the production process that we deeply regret. We will be taking the necessary steps to prevent this from happening in the future and apologize to viewers."
Attorney Craig Sonner said Monday that Zimmerman would hand himself in if charges were filed against him.
"If he is asked, he will turn himself in," Sonner said. "There's not going to be a manhunt or anything like that. We're preparing for trial. We've done all we can except ask for discovery [evidence-sharing] from the state, which is not available to us yet."