When Bill Lee Jr. took over as police chief in Sanford, Fla., last May, he promised to polish the force’s image and clean up an agency that had lost the confidence of many residents, particularly in the black community.

Trayvon Martin

Trayvon Martin

But last month’s shooting death of Trayvon Martin — an unarmed black teenager who police said was shot by a white neighborhood watch captain — has reopened old wounds. The police have not arrested George Zimmerman, 28, who is white, and who police said admitted to shooting the teen in self-defense.

Read more about the case here.