SANFORD, FLA. — The police chief who’s been bitterly criticized for not arresting a neighborhood watch volunteer in the shooting death of an unarmed black teenager and the county prosecutor both left the case Thursday, with the chief saying that he is temporarily stepping down to let passions cool.

Sanford Police Chief Bill Lee’s decision came less than a day after city commissioners gave him a “no confidence” vote, and after a couple of weeks of protests and uproar on social media websites. Lee has said evidence in the case supported George Zimmerman’s assertion that the Feb. 26 shooting of 17-year-old Trayvon Martin was in self-defense.

“I do this in the hopes of restoring some semblance of calm to a city which has been in turmoil for several weeks,” Lee said.

About three hours later, Gov. Rick Scott announced that the local state attorney, Norman Wolfinger, had recused himself from the case. In a letter to Scott, Wolfinger said that while he thought he could fairly oversee any prosecution that develops in the case, his recusal was aimed at “toning down the rhetoric and preserving the integrity of the investigation.” Scott appointed Angela B. Corey, the state attorney for the Jacksonville area, to take over the case.

Scott also appointed a task force led by Lt. Gov. Jennifer Carroll to conduct hearings on the case and to make recommendations for any changes to state law or procedures. Carroll is African-American.

Martin was returning from a trip to a convenience store when Zimmerman started following him, telling police dispatchers he looked suspicious. At some point, the two got into a fight and Zimmerman pulled out his gun.

Zimmerman told police Martin attacked him after he had given up on chasing the teenager and was returning to his sport utility vehicle. Police say the 28-year-old Zimmerman is white; his family says he’s Hispanic.