ORLANDO, Fla. — The Crimeline reward for tips leading to an arrest in the fatal shooting of Boone High School student Alejandro Vargas Martinez has been increased to $15,000, according to deputies.

The 15-year-old was shot and killed while walking to school December 18, 2018 around 6:30 a.m. at Waldo Street and East Kaley Avenue.

The reward was initially set at $10,000 in December, according to Orange County Sheriff’s Office, but the amount has since been increased to $15,000.

No motive or suspect information has been released, but deputies have shared surveillance video of a vehicle of interest described by officials as a four-door sedan.

The lead detective in the case says there were witnesses investigators still have not yet talked to.

“We don’t know if they’re witnesses or suspects, but we know there were other people present that we have not spoken to at this point," said Brian Savelli with the Orange County Sheriff’s Office.

Anyone with information is encouraged to call Crimeline at 407-423-8477, or the Orange County Sheriff's Office at 1-407-254-7000. Crimeline callers can remain anonymous.

Reporter Jeff Allen contributed to this story.