ORLANDO, Fla. (WOFL FOX 35) - It's been 15 days since someone fatally shot 15-year-old Alex Vargas Martinez at 6:38 in the morning, as he was walking to Boone High School.
Lead Detective Brian Savelli is now saying someone besides Alex and the killer knows what happened.
"Whether they were witnesses or suspects, we don't know at this point. But we know there were other people there," he said. "We know that people are hesitant to talk to law enforcement so we want them to realize this kid was a good kid."
Crimeline is now upping the reward to $15,000 for information in this case, hoping it will encourage someone to come forward.
"If you talked to anybody that knew him, I couldn't find anybody to say one bad thing about him," said Detective Savelli. "The one thing that struck me the most is the last phone conversation he had with his mom he told his mom I put some money on the counter to help you pay bills."
The Orange County Sheriff's Office is not releasing any possible motives yet in this case. They also won't say if someone was following Alex, casing him, or if this was a case of mistaken identity. Right now, investigators say they're anxiously awaiting the tip or the witness pointing investigators to who killed the Alex.
"Just because you were there and you witnessed something, does not mean that's a bad thing. You were just at the wrong place at the wrong time and we're asking you to come forward," Detective Savelli said.
Alex would have turned 16 on New Year's Day. The teenager's family left "Happy Birthday" balloons and cupcakes at the makeshift memorial, where detectives say Alex was killed. Wednesday is Alex's mother's birthday. The family says all she wants for her birthday is to know who killed her son and why.