Under mounting pressure, the city of Sanford, Fla., has released a letter to the public about why George Zimmerman, who fatally shot an unarmed black teenager in the city last month, was not arrested. The letter calls the death of Trayvon Martin “morally appalling.”

A 2005 mug shot of George Zimmerman, released by the Orange County jail in Florida. (AFP/GETTY IMAGES)

The letter goes on to address a number of questions that Bonaparte says the city has received repeatedly the last month.

Celebrities, politicians, African American leaders and civil rights leaders and online petitions have all called for Zimmerman’s arrest. Zimmerman’s father maintains that “at no time did George follow or confront . . . Martin.”

Among the questions is whether Zimmerman broke any laws in holding a concealed weapon as a neighborhood watchman. The letter says that because Zimmerman had a permit to carry a weapon in a concealed manner, he broke no laws in having a gun. Some activists have used this case as leverage to lobby for stricter gun control laws in Florida.

The letter also addresses the 911 calls released this past weekend, in which Zimmerman tells the dispatcher he is going to follow Martin and the dispatcher responds: “You don’t need to do that.” Many people have asked whether that exchange can be used in the investigation. According to the letter, the dispatcher’s suggestion is not a lawful order that Zimmerman would have been required to follow.

Finally, the letter seeks to assuage some of the anger directed at Sanford. Many have accused the city of racism.

“As a father, I can only image the pain Trayvon’s family must be going though,” writes Bonaparte. “Although the Police Department is the target of the troubling questions, let me assure you we too feel the pain of this senseless tragedy that has dramatically affected our community.”

The city is now being assisted by the U.S. Department of Justice and FBI, which have opened a criminal investigation into Martin’s death.