Sweat, the boy's mom, told the St. Petersburg Times that the mayor had come because her son had counseled teens against participating in gang violence.
The boy's Facebook page shows him with a wad of cash in his mouth and a tattooed arm held up to show his watch. He refers to himself as 'Young Savage' in his profile.
Friends of the teen have formed a Facebook group called "Free Nick."
The slain officer, Crawford, was eligible for retirement. He leaves behind an adult daughter and a wife.
"It breaks my heart," police chief Harmon said. "When you have something like this happen, you don't expect this type of confrontation between a 16-year-old and a police officer to end like this."
Crawford is the third police officer to die in St. Petersburg in less than a month. The city had seen no police deaths in 30 years until last month when two police officers were ambushed by bullets in an attic of a home.
The officers had gone to the home to interview a relative of someone wanted for aggravated battery.
ABC News' Russell Goldman and the Associated Press contributed to this report.