$10K reward offered in mysterious case of newborn found dead off Florida coast

The newborn -- dubbed "Baby June" by the sheriff's office -- was most likely 4 to 7 days old, giving her a birth date between May 25 and 28, the sheriff's office said Thursday.

Palm Beach County Sheriff Ric Bradshaw called the baby's death a "horrific and horrible tragedy" that has "really struck a nerve with me."

Bradshaw is offering a $10,000 reward for anyone with any information that leads to the arrest of the person or persons responsible.

"It's incomprehensible to me that people out there that have information about this case have not come forward," Bradshaw said.

Police released an artist rendering image of how the baby may have looked at birth.

PHOTO: On June 4, 2018, the Palm Beach Sheriffs Office released this sketch of a female infant that was found dead off of Boynton Beach, Fla., on June 1.

The baby was most likely mixed race, black or Hispanic, the sheriff's office said.

It appears she was floating in the water for about 6 to 18 hours, the sheriff's office said.

Investigators believe the baby came from Broward County, the sheriff's office said, though authorities declined to elaborate on how they reached that conclusion.

Authorities "desperately want to get to the bottom of what happened," Palm Beach County Sheriff's Office Special Victims Unit Captain Steven Strivelli told reporters Monday.

Anyone with information is urged to call the Palm Beach County Sheriff's Office at 561-688-4155.