Nick Lindsey arrived home about 11 p.m. Monday and his mother said she immediately knew something was wrong.
"I know my child," Deneen Sweat said. "I asked him to tell me what happened, and he wouldn't."
On Tuesday, she saw the surveillance video of the suspect in the fatal shooting of a police officer the night before. The 20 seconds of footage showed someone wearing a hoodie, long shorts, white socks and sandals and ambling along a downtown sidewalk about 90 minutes before the killing.
It was then she learned what was troubling her son, a 16-year-old Gibbs High School sophomore.
"I knew it was him," she said. "I told him to man up."
Hours later, Lindsey was under arrest, bringing to an end a massive manhunt that had kept the city in its grip for almost a day.
The teen faces one count of first-degree murder in the death of veteran St. Petersburg police Officer David Crawford, who was shot at least four times while responding to a reported prowler.
Sweat said her son told her he bought the gun for $140.
She said she believes the shooting was accidental and occurred when her son was pulling the gun from his pocket - a version of events that clashes with that outlined by authorities, who say Crawford exchanged gunfire with his killer.
Police also said the family had no clue Lindsey was a suspect until officers arrived at their apartment while following leads.
Anthony Sweat said his half-brother apologized but also maintained his innocence during a brief visit at the county's juvenile detention center.
"As far as I can tell he was really sorry," said Sweat, 19. "He cried to me and let me know that he was sorry for letting me down."
Authorities said Lindsey has prior arrests for auto theft, but none involving violence.
Gibbs High classmate Tiara Davis said she has known Lindsey for seven years, describing him as "quiet and straight. No one hated him."
Wearing a white T-shirt with the words "Free Lil' Nick" written in marker, Davis said the neighborhood "is very shocked by the charges against him."
"He's not the kind of person to do such a thing," said another classmate Destiney Newsome. "But if you're in that kind of neighborhood after 10:30, who wouldn't walk around with a gun?"
Ben Fortner, who coached Lindsey on the Lil' Devils Pop Warner team, said he was a "very respectable kid" who fell in with the wrong crowd about two years ago.
"I don't want to sugarcoat things," said Fortner, who is the teen's uncle by marriage. "This is what happens when you hang with that type of crowd."
Lindsey was born into a troubled world.
The year before, his biological father, Nicholas Lindsey, pleaded guilty to operating a crack house and other charges. He was sentenced to six months in jail.
Lindsey Sr., who also goes by Nicholas Lindsay, continued to rotate in and out of jail on drug charges in the years ahead, court records show.
The month before she gave birth to Nick, Deneen Sweat agreed to hand over custody of then 4-year-old Anthony to his father, who is not Lindsey Sr.
Sweat had recently lost her job as a licensed practical nurse at Bayfront Medical Center due to illness and surgery, records show, and had been ordered into a pre-trial intervention program after pleading no contest to a bad check charge.
Sweat, who also has a 4-year-old son by a third man, sued Lindsey Sr. in 2006 for child support. At the time, he was in a work release program stemming from a criminal case.
Lindsey was ordered to pay almost $340 a month, records show.
Sherry Howard, a family and community liaison at Gibbs High, has worked with the younger Lindsey since middle school, counseling him to make good choices. She said he was respectful and didn't have anger issues.
Lindsey was smart and capable but had attendance issues, she said, and had missed "about 40 days this year. ... I don't know why he wasn't coming."
Although it wouldn't shock her to see some other students get arrested for serious crimes, Howard said, "This boy wasn't that kid."
On his Facebook page, Lindsey is shown with a wad of money in his teeth and his hands clenched into fists. The photo is emblazoned with the words "hood rich."
Sweat said his brother isn't a thug.
"It's not like my brother to tote a gun," he said. "He's not a cop killer."
At his son's initial court appearance Wednesday, Lindsey Sr. apologized for the shooting and offered his family's sympathies to Crawford's family and colleagues.
Father and son cried as they stood before Judge Raymond Gross.
Gross thanked the elder Lindsey for his statement and said Crawford's slaying hurt not just the city but the state and perhaps the nation.
Lindsey Sr. had one question for the judge.
"Can I hug my son?" he said.
"I can't do that, sir," Gross replied. "I can't do that."