(CNN) -- An 18-year-old man and his 13-year-old girlfriend are suspected of stealing three cars -- two with guns inside -- and are the subjects of a law-enforcement search that stretches from Kentucky to Georgia -- and maybe on to Florida.
Dalton Hayes, 18, and Cheyenne Phillips, 13, are "increasingly brazen and dangerous," Sheriff Norman Chaffins of Grayson County, Kentucky, said in a press release.
"I know Dalton and he has a history of making bad, bad decisions," said Chaffins, sheriff for the county of about 25,000 people in central Kentucky. "I was the school resource officer before I was elected sheriff. Dalton is known to have disciplinary and defiance issues at the high school with authority."
Hayes was recently charged with burglary and was out on bond, the sheriff said. He's worried things will end badly as the two get farther and farther from home.
"They are in strange territory," Chaffins said. "We are a local, tight-knit community here, we just want them home ... other agencies see them as criminals stealing cars. They would be treated differently than they would be in our county."
It was not clear late Friday whether any formal charges have been filed against either teen. The sheriff has referred to them several times as "suspects."
Cheyenne's father reported her missing January 3 from Clarkson, Kentucky. Chaffin said she was thought to be in the company of Hayes.
The couple stole a Toyota vehicle that day in Clarkson, crashed it and fled on foot, Chaffins said. A local resident discovered them inside his garage, the sheriff said.
"The citizen confronted them, they asked for water and then they fled," he said.
An hour later, the couple stole a 2006 Toyota Tacoma pickup truck with a firearm inside it, Chaffins said.
Both teens are suspects in the two felony auto thefts and Hayes is wanted for custodial interference.
"It is imperative that these two be located and apprehended as their behavior is becoming increasingly brazen and dangerous," the sheriff said in a press release.
On Wednesday, the sheriff's department said the couple was spotted on security-camera video at a Wal-Mart store in Manning, South Carolina. The girl was wearing pink cowboy boots, and the man with her was dressed in a dark-colored University of Kentucky T-shirt, the department said.
On Thursday, authorities said the Toyota Tacoma pickup stolen in Kentucky was recovered in Henry County, Georgia, just south of Atlanta.
A silver 2001 Toyota Tundra pickup with a Georgia certified firefighter license plate was reported stolen from the area around the same time. That truck had two handguns -- a .38-caliber and .a 45-caliber -- inside, the sheriff's department said.
The sheriff said the two teens may be headed to Florida.
"They are becoming increasingly desperate and we just hope they have enough sense to do the right thing," he said.