A teenage girl who ran away to rendezvous with a high-risk sex offender she met online was found safe at a store 400 miles from her home on Tuesday, while the search for the 46-year-old man continued, a sheriff said.

Authorities had issued an Amber Alert, blasting photographs of the two and a description of the suspect's car across the state after the girl sneaked out of her home early Monday.

Polk County Sheriff Grady Judd made a direct plea in a nationally televised news conference to William Joe Mitchell to leave the girl somewhere, and believes it worked.

"For some reason, he knew it was time to run," Judd said. "And thankfully he didn't murder her before he did that." Mitchell of Jacksonville was believed to be armed with a handgun.

The girl, 15, was located at a Wal-Mart in the Florida Panhandle, the sheriff said. The girl told authorities the two separated when Mitchell took her into the store.

Mitchell left her in the clothing department and said to find him by the electronics in 5 minutes, Judd said. Mitchell told the girl he'd kill her if she drew attention to herself, but Judd said it was clear he meant to drop her off.

The girl's parents were "elated," the sheriff said.

Judd said the girl had been chatting online with Mitchell and believed him to be a young man — maybe 20 or 24. He said police didn't know where the two were or what happened.

"He truly had her convinced that he was a young man in love with her," Judd said. "He, on the other hand, knew he was grooming a child to engage her in sexual conduct. Whether that occurred or not we don't know and we won't release."

The Associated Press is no longer identifying the girl or transmitting photos of her because she is a suspected victim of sexual abuse. It did so earlier in the interest of her safe recovery.

Judd also said the pair crossed the state line into Alabama at some point, and he would talk with officials there to see about federal charges.

"We know, from all of the investigation up to this point, that they left together," Judd said before she was found. The girl contacted some of her friends and said that she was running away.

"When they asked, 'Well, why are you running away?' She told them 'for love,"' the sheriff said.

Judd said Mitchell had 14 prior arrests on charges including burglary, aggravated assault with a weapon, grand larceny, bomb threats, extortion and offense or offer of lewdness and lewd and lascivious behavior.

Judd said it wasn't clear how many times Mitchell had been convicted, or of what, but he was under state supervision.

"Why wasn't he in prison to begin with?" Judd said. "Our goal is to take him into custody and that he stay in prison for the rest of his natural life so no other child can be the victim of his conduct."

The girl ran away the day a new Florida law took effect, making the state's sex predator penalties some of the toughest in the nation.

The law requires offenders to register e-mail and instant message handles with authorities, information that will be shared with social networking sites like Myspace.com. The state also tripled the maximum sentences to 15 years for soliciting minors for sex and possessing child pornography.