The passenger removed from the US Airways flight did nothing wrong and was the victim of "a pretty nasty trick," Philadelphia police Chief Inspector Joseph Sullivan said.
Officials would not identify the man, but Philadelphia resident Christopher Shell identified himself in a phone call with The Associated Press as the person at the center of the midair drama.
Shell declined further comment. His Facebook page is filled with references to the episode and even photos of Shell aboard the plane before departure.
"We just spent a half-hour in the air to be notified that the plane, `has technical difficulties' and had to fly back! Flight 1267 CANCELED," Shell later wrote, apparently unaware he was the reason for the return.
Sullivan said police at Philadelphia International Airport received a call around 7:30 a.m. that named a passenger who was on his way to Texas and carrying a dangerous substance.
That name matched a passenger on board Flight 1267 to Dallas-Fort Worth International Airport, prompting officials to decide to turn the aircraft around after it had already flown a third of the way across Pennsylvania.
After landing, the airplane taxied to a remote section of the airport, where a slew of law enforcement vehicles surrounded it. Authorities escorted Shell from the airplane and put him in the back of a police car.
Sullivan said the targeted passenger was very surprised to be approached by officers.
"He was obviously very alarmed, as I would be if heavily armed police officers entered a plane to take me off," Sullivan said. "And he was certainly stunned. And that's why this is no joke, this is no laughing matter."
Bomb technicians and specially trained dogs searched the plane but found nothing illegal or hazardous, Sullivan said.
Sullivan stressed that the passenger is not a suspect and did nothing wrong. Police are treating the hoax seriously because it had resulted in a heavy police response and a significant hassle for all those on board, he said.
"It's just an incredibly foolish and irresponsible thing to do and, bottom line, it's criminal," Sullivan said.
Earlier, an FBI spokesman said the flight was diverted because of a call reporting liquid explosives were on board.
Sullivan declined to discuss the content of the call, but FBI spokesman Frank Burton said it came in minutes before the flight was scheduled to depart at 7:39 a.m. Burton said police, the FBI and the airline worked quickly to get the plane on the ground.
Shell's hometown is Fort Worth and he works in Philadelphia for 2020 Companies, a sales and marketing firm, according to his Facebook page. He wrote on Facebook that he was flying home to Texas to celebrate his 29th birthday.
The airplane had 69 passengers and five crew members on board, airport spokeswoman Victoria Lupica said.
Sullivan said the investigation into the phone call had been turned over to the FBI.
FBI Special Agent Richard Quinn said it was too early to speculate about what sort of charges could be filed against the caller, but they could be severe.