News and Investigations

Polk County Sheriff's deputies arrested three teenaged car thieves 15 hours after they stole an SUV from within the city limits of Winter Haven on Saturday, September 27, 2025.

The victim reported the theft of his 2020 GMC Terrain to the Winter Haven Police Department around 8:45 a.m. that morning. Around 11:45 p.m., information was received by the PCSO regarding the stolen vehicle heading west down Winter Lake Road from US Hwy 17 in Winter Haven.

PCSO deputies and the helicopter responded to the area, and a deputy sheriff spotted the stolen SUV parked at the Circle K store on Spirit Lake Road at Winter Lake Road. He strategically parked and awaited back up, noticing two teenagers dressed in dark clothing walking out of the store and approaching the SUV (while a third suspect was still was sitting in the driver's seat, his foot on the brake). When the two suspects on foot spotted the patrol vehicle, they started making hand gestures to the driver while also walking away. The driver backed out of the lot, and the deputy followed. The Lieutenant on duty arrived at the store at the same time and drove towards the suspects fleeing on foot. He jumped out of his patrol vehicle and ordered them to stop. As they refused to comply, another deputy showed up and assisted the Lieutenant with taking them into custody. These two suspects are Mason Stepney, 15, and Thailyn Polynice, 16, both of Winter Haven.

Additional units responded as backup with the helicopter overhead, to assist with the traffic stop on the fleeing stolen GMC. The suspect/driver headed north on Spirit Lake Road and fled for approximately one mile before slowing down and eventually stopping, surrendering to deputies. He is Henry Joiner, 16, of Poinciana.

Stepney told deputies that Joiner picked him in the SUV and they picked up Polynice from the bowling alley in Winter Haven. Then they headed to the store to buy drinks. They admitted to having marijuana and planning to smoke it that evening. Joiner told deputies that Stepney picked him up from the bowling alley. Polynice told deputies that Joiner, who was driving with Stepney in the front seat, picked him up from the bowling alley.

Stepney and Joiner were wearing black masks over their faces to conceal their identities.

Deputies located the marijuana belonging to the suspects inside the stolen vehicle. They were all three arrested and taken to the Juvenile Assessment Center. The GMC was returned to its owner.

Joiner is charged with:

• Grand theft of a motor vehicle (F3)
• Fleeing to elude (F3)
• Reckless driving (M2)
• Possession of marijuana (M1)
• Possession of paraphernalia (M1)
• Keeping a vehicle for drug use (M1)

Stepney is charged with:

• Grand theft of a motor vehicle (F3)
• Possession of marijuana (M1)
• Possession of paraphernalia (M1)
• Resisting arrest (M1)

Polynice is charged with:

• Grand theft of a motor vehicle (F3)
• Resisting arrest (M1)

He has a prior arrest for battery.

“I'm very proud of my team for swiftly apprehending these juvenile felons before they could commit any more crimes in the county. While they are all facing serious charges, there is still time for them to make better decisions and turn their lives around. We hope that they heed that advice.” – Grady Judd, Sheriff