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Trayvon Martin: Police chief temporarily steps down
Florida residents have expressed their sorrow and concern over the death of Trayvon Martin. Video by the BBC's David Botti
A Florida police chief criticised over the investigation into the shooting of an unarmed black teenager has announced he will temporarily step down.
Bill Lee has been censured by officials in Sanford, an Orlando suburb, over the death of Trayvon Martin.
A mass rally led by civil rights leader Reverend Al Sharpton is being held to demand justice for the 17-year-old.
Neighbourhood watchman George Zimmerman, 28, was not charged for shooting the teenager.
He said he was defending himself because Mr Martin had attacked him. In Florida, a law known as "stand your ground" can prevent criminal or civil prosecution when deadly force is used in self-defence.
Mr Lee explained his decision at a news conference on Thursday afternoon.
'City in turmoil'"It is apparent that my involvement in this matter is overshadowing the process," he said.
Analysis
Is there tension in Sanford? Yes. As I open the gate into The Retreat At Twin Lakes, hoping to find someone to talk, a woman in a black SUV angrily threatens to report me for trespassing. Another couple, out for an evening walk, tell me that everyone is on edge and they worry about what might happen.
And in a gun shop back in the rundown part of town, the staff - who won't be interviewed or identified - tell me that on Tuesday they refused to sell weapons to two black men who seemed to be spoiling for a fight.
For all the anger and the frustration evident here, Sanford doesn't feel like a powder keg, waiting to explode. People sense that with the justice department involved and a Florida grand jury set for next month, the wheels of justice are turning, however slowly.
"Therefore I have come to the decision that I must temporarily remove myself."
"I do this in the hope of restoring some semblance of calm to the city, which has been in turmoil for several weeks," he added.
Mr Lee's decision to stand aside comes a day after city commissioners in Sanford issued a vote of no-confidence in him.
They voted 3-2 to censure the police chief, who has held his position for just 10 months.
Mr Lee's decision was welcomed by Ben Jealous, president of the National Association for the Advancement of Colored People (NAACP), the Orlando Sun Sentinel newspaper reports.
But Tracy Martin, the victim's father, was cheered as he told Thursday's rally: "The temporary step down of Bill Lee is nothing. We want an arrest, we want a conviction."
Mr Martin's parents have met officials from the Department of Justice, who have launched a civil rights investigation into police conduct of the case.
Nearly one million people have signed online petitions calling for justice.
The shot teenager's father was flanked at the demonstration by Mr Sharpton, who said: "We came for permanent justice. Arrest Zimmerman now! Investigate the entire police department now."
The civil rights leader tweeted earlier that he was attending the rally despite the death of his mother, who passed away on Wednesday.
In anticipation of large numbers of protesters, the rally venue was moved from a 400-seat church to Fort Mellon Park in Sanford.
Meanwhile, Mr Zimmerman has been removed from Seminole State College, where he was studying, the Orlando Sun Sentinel newspaper reports.
The head of police in the city of Sanford, Bill Lee: 'My role as leader of this agency has become a distraction'
"Due to the highly charged and high-profile controversy involving this student, Seminole State has taken the unusual but necessary step this week to withdraw Mr Zimmerman from enrolment," the college said.
On Wednesday, Mr Martin's parents addressed a mass rally in New York to call for the arrest of Mr Zimmerman.
His father, Tracy Martin, told the so-called Million Hoodie March that police had racially profiled his son.
'Tragic situation'Although Mr Martin was killed in late February, the publication of 911 emergency calls and sworn testimony from a friend have fuelled debate over whether the shooting was truly a case of self-defence.
A Florida grand jury is considering whether there is enough evidence to file charges, and the US justice department has launched a probe into the local police investigation.
In a statement Sanford City Manager Norton Bonaparte called the death of Mr Martin a "tragic situation".
But he emphasised that officers of the Sanford police department were "prohibited from making an arrest based on the facts and circumstances they had at the time".
Recordings of emergency calls suggest that police told the shooter not to go after Trayvon Martin
Mr Martin was unarmed and on his way home after buying sweets from a local shop, his parents say.
Transcripts of phone calls released by police indicate that Mr Zimmerman called the police after seeing Mr Martin, describing him as "real suspicious".
The recordings suggest the police dispatcher told Mr Zimmerman not to pursue the teenager.
Mr Zimmerman has said he shot Mr Martin to defend himself after the teenager attacked him.
Details of the confrontation remain unclear.
Florida's self-defence law, enacted in 2005 and known as "stand your ground", gives people scope to use deadly force rather than retreat during a fight.
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