HAMMOND, La. (AP) _ A teen-ager charged with killing three fast-food restaurant employees in a $1,700 robbery changed his mind a third time Friday and decided to fight extradition just 90 minutes before he was to fly to Florida.

Earlier Friday, lawyer Mike Nunnery had said 17-year-old Burnell Hegwood, formerly of Hammond, would fight the return to Fort Lauderdale. On Thursday, Hegwood had said he would waive extradition.

Fort Lauderdale detectives had been scheduled to fly to Florida with Hegwood late Friday, according to Hammond Police Sgt. Kenneth Corken.

''We just want to find out more information in order for them (Florida officials) to justify an extradition,'' Nunnery said after the latest decision. ''It's my belief he is innocent. He's probably trying to protect someone who is close to him.''

Hegwood, who worked in the kitchen of the Wendy's restaurant for 3 1/2 months, was named in a warrant Wednesday as a suspect in the shootings of Wendy's manager, William Schmidt, 46, and employees Michael Peters, 21, and Sharon Reeseman, 19.

Hegwood, who moved to Fort Lauderdale earlier this year, was arrested about midnight Wednesday as he and a 16-year-old girl friend stepped off a Greyhound bus from Florida. The girl friend was questioned and later released, police said.

Hegwood admitted the crime after more than 2 1/2 hours of interrogation at the Hammond City Jail, according to Fort Lauderdale homicide Detective Mike Walley.

Schmidt was preparing to open the restaurant with Peters and Miss Reeseman when the three were shot to death last Saturday. Police believe the assailant entered through the rear door.

''It was just a bad day and he just wanted to have a lot more money than he had when he woke up that morning,'' said Gary Ciani, another Fort Lauderdale detective.