TAMPA — Since he was 10 years old, Larry Donell Brown has taken whatever he wants.

When he was just a 67-pound kid, he stole Starburst from a gas station. Years later, he pummeled a teenager for his MP3 player, a police report states, and snatched a woman's purse. He punched a cashier in the mouth after taking Newport cigarettes.

Brown was not above violence to get stuff, according to police reports. The 16-year-old turned to it again the night before Thanksgiving, police say, when he wanted something from an East Tampa private security officer.

And this time, he had a gun.

Brown shot the officer dead, police say, but got nothing.

He fled empty-handed, leaving behind a bicycle that police used to connect him to the scene. It had his DNA on it. That, along with witness statements, material evidence from a friend's apartment and surveillance video, led detectives to Brown.

He was arrested on a first-degree murder charge Wednesday. Police are asking prosecutors to charge him as an adult.

Police deal with juveniles every day, but Brown stood out even in their books. They have charged him 36 times in six years. He has been convicted of 12 felonies.

He was on probation Nov. 21 when he confronted security officer Michael Valentin, 38, at the Grande Oaks Apartments, Tampa police say.

Brown was visiting a girl. He had a stolen Taurus 9mm gun.

The officer had a gun, too, but it was still in his holster when authorities arrived. The security officer, a husband and father of two, was already dead.

His funeral is today.

The chief of security firm Critical Intervention Services, where Valentin worked, said Thursday he was heartened that police made an arrest before the funeral.

"To know that person is off the street is the best that we can do, under the circumstances," said KC Poulin, adding he was thankful for Tampa police's hard work.

He also released a statement from Valentin's widow, Shanequa "Nikki" Valentin: "We the family are extremely grateful for the diligent work of the Tampa Police Department. . . . We are taking the time to celebrate Michael's life. We are very proud of Michael and his service he has provided."

• • •

Brown grew up in Tampa, raised by a mother who gave birth to him when she was 15.

He was too much for her by the time he was 13.

His mother, Nicole Bailey, told officers in 2010 that Brown had been running away and wanted to be in a gang. She said she couldn't control him, a Tampa police report states.

When he stole an Xbox and television from a friend after a sleepover, she called police.

Why did you take it? an officer asked.

"I just wanted it," Brown replied.

A woman at the family's apartment declined comment Thursday. Neighbors in the complex off Sligh Avenue stood outside, talking about Brown's arrest. Among them were his friends.

Brown was known for getting in trouble, they said. Still, they were surprised. Murder?

"I know he didn't do nothing," said Chris Wilford, 21, who said he was a cousin. "He's really not that type of person that would kill someone like that. … We gamble, we drink, but I don't think he would do something like that."

Brown likes football, basketball and pool, they said.

"I wouldn't expect him to do anything like that," said another friend, Alex Walker, 18.

Steve Johnson, 16, said he has known Brown since middle school.

"I know he's done time," Johnson said, "I also know he cared about other people."

On Tuesday, police had announced a $10,000 reward for a tip leading to the arrest of whoever killed Valentin. The money would be provided by CIS.

But it appears it was police work that led detectives to Brown, not one tip in particular.

Two nights after police say Brown shot Valentin, they say he robbed a man at an automated teller machine at gunpoint. Four nights later, on Monday, police say, Brown rode his bicycle to the same Bank of America by University Square Mall and again held a gun on a man at the ATM.

That man, Husain Baaqel, 25, didn't know what to think. Was it a toy? He gave Brown $40 and his iPhone, he said.

Baaqel, who plans to graduate next month with a degree in chemical engineering, has an 8-month-old child. All he could think of was his wife and baby.

Brown never fired the gun.

But police say the 16-year-old had the same 9mm that he used to shoot Valentin on him that night. When Baaqel heard the news Thursday, he was shocked.

"I feel lucky," he said.

Police detained Brown on Tuesday, and questioned him in connection with a firearm theft. It appears, they say, that the gun had been stolen in the county.

Police also questioned him in Valentin's murder. Meanwhile, authorities searched an apartment of one of Brown's "associates," where they found evidence. The Florida Department of Law Enforcement connected DNA samples on the bicycle to Brown.

Brown was being held at the Juvenile Assessment Center.

Times news researchers John Martin and Tim Rozgonyi and staff writers Stephanie Bolling and Keeley Sheehan contributed to this report. Jessica Vander Velde can be reached at jvandervelde@tampabay.com or (813) 226-3433.