Police chief in Stand Your Ground killing steps down SANFORD, Florida (Reuters) - The police chief of a Florida town where an unarmed black teenager was shot dead by a neighborhood watch captain stepped aside on Thursday following withering criticism and national outrage that police have declined to arrest the shooter. Sanford Police Chief Bill Lee's resignation - which he called "temporary" - failed to appease civil rights and community leaders who are calling for the arrest of watch captain George Zimmerman, 28, who shot 17-year-old Trayvon Martin and has claimed self-defense. Police have said Florida's "Stand Your Ground" law, which allows people to use deadly force when they perceive danger in any public place, prevented them from arresting Zimmerman, a white Hispanic who has disappeared from public view. Zimmerman's father said his son was unfairly vilified by the case, calling him a friend of minorities whose true nature was being distorted by national calls for his arrest and allegations he pursued Martin just because he was black. Coupled with at least two prior cases that stoked black anger toward the police, the response to the Martin episode had grown so intense that Lee said he had no option but to step aside because "my involvement in the matter is overshadowing the process." In 2011, a previous Sanford police chief was forced out of the job after a white police officer's son was captured on video sucker-punching a black homeless man outside a bar. Sanford police did not immediately arrest the officer's son, Justin Collison. But after video of the attack surfaced on local TV and the Internet and provoked an outcry from Sanford civil rights leaders, Collison was charged weeks later with aggravated battery and disorderly conduct. He eventually pleaded guilty to a misdemeanor charge. The incident came five years after two white private security guards with ties to the police department shot and killed a black teenager. The two guards - one the son of a Sanford police officer and the other a department volunteer - said they opened fire in self-defense, claiming the teenager attempted to run them over. Evidence showed the teenager died from a gunshot in the back. The cases were eventually dismissed because of a lack of evidence. The case generated mostly local interest in the days following the February 26 shooting but has steadily drawn the national spotlight, which has only grown in recent days since the state of Florida and U.S. Justice Department announced their own investigations and the city commission voted 3-2 in favor of a "no confidence" motion against Lee on Wednesday night. Florida Governor Rick Scott and Attorney General Pam Bondi on Thursday replaced the head of the state investigation, appointing Angela B. Corey as the "assigned" state attorney to place Norman Wolfinger, who said he stepped aside to avoid "even the appearance of a conflict of interest." Scott also announced the formation of a task force to follow up the findings of Corey's investigation. A crowd of at least 5,000 and growing gathered in a Sanford park to protest the Martin case and what black leaders have called a pattern of racial discrimination in Sanford and elsewhere in a country that nonetheless has elected a black president. "There are serious problems that go beyond this case," said Benjamin Jealous, president of the National Association for the Advancement of Colored People, a leading civil rights organization. Sanford City Commissioner Patty Mahany said relations between the police and blacks were poor well before Lee took charge of the department 10 months ago. Rather than any single scandal, she said the trouble amounted to "smaller, more insidious things, but that were still part of that whole culture that were present at that time in the police department." The African American community here in Sanford feels very strongly that they were treated differently. It seems to be the very same complaints you hear on a national level: the reasons for police stops, things that were said to them at police stops, the way arrests were handled and investigations were handled," she said. Sanford City Manager Norton Bonaparte, who is black, told Reuters he understands the outrage over the killing and acknowledges the case "does conjure up a negative image of our city and it is disturbing." There is the race issue. That's indisputable," he said. The case has also drawn attention to Florida's controversial self-defense law, which was enacted in 2005. Since then more than 20 U.S. states have adopted similar laws, but now Florida politicians, including Governor Scott, are reconsidering the law. Late last month, Martin was returning to a gated community from a candy run at a convenience store when Zimmerman, carrying a licensed handgun in his role as a neighborhood watch captain, saw him. Additional reporting by Barbara Liston and Kevin Gray; Writing By Paul Thomasch and Daniel Trotta; Editing by Lisa Shumaker