TAMPA (FOX 13) - The trial of a man accused of killing an apartment complex security guard is underway in Hillsborough County.
Defendant Larry Brown is charged with fatally shooting Michael Valentine in 2012.
Valentine sent his last text message to his niece, Jasmine, minutes before he was gunned down.
"I wanted to ask him a question, and he texted back, 'Sure go ahead,'" Jasmine testified.
Around the same time, truck driver Donald Williams was driving into the Grand Oaks Apartments and greeted Valentine at the guard gate.
"I noticed there was a guy on a bicycle riding real slow," said Williams.
Two minutes later, as Williams drove out of the complex with his stepson he heard shots fired.
"It sounds like a gunshot or a loud firecracker," explained Williams.
He then spotted Valentine on the ground.
"I told my stepson, 'I'm going to go check on him.' I observed uh, he had a gunshot to the rear of the head," said Williams.
He also saw a bike next to Valentine's body. Prosecutors said it's the one Brown was riding the night Valentine was murdered.
Investigators said Brown, who was 16 at the time, shot Valentine so he could steal his gun, but he couldn't unlock it from the holster.
Prosecutors said Brown stole his mothers gun to kill Valentine.
Days later, Brown allegedly robbed two people, including Hussain Baaquel, at gunpoint at an ATM.
Baaquel is expected to testify at the trial. He talked to FOX 13 a few years ago after the murder.
"After I heard someone was killed, every time I remember that gun, my God, it's scary," said Baaquel.
Brown's attorney, Jennifer Welker, dismisses the state's case as weak, claiming there is no DNA or physical evidence.
"You will find reasonable doubt in this case. You will reach a verdict of not guilty because Mr. Brown is not guilty," Welker said to jurors.