OKLAHOMA CITY (AP) _ Smart and funny with bright red hair and freckles, 10-year-old Jamie Rose Bolin liked to pillow fight with her sisters and play with Barbie dolls.

``She had a giggle that you couldn't help but join in,'' said Jamie's grandmother, Rose Fox. ``She was the kind of girl who could just light up a room.

``She liked to wrestle with her little sisters and wrestle with her 'poppa,' which is my husband. She liked puppies and kittens and all the other things little 10-year-old girls like.''

On Friday, Jamie's body was discovered in her neighbor's apartment downstairs at the Purcell apartment complex where she lived.

Police arrested Kevin Ray Underwood, 26, on a first-degree murder complaint and took him to the McClain County Jail, where he was being held without bail on Saturday. Prosecutors said they expect to file formal charges on Monday and that they intend to seek the death penalty.

Purcell Police Chief David Tompkins said Underwood had no apparent criminal record. It was not immediately known whether Underwood had a lawyer.

Underwood drew the suspicion of investigators when he pulled up to a check point set up in the area near the apartment complex on Friday, said Oklahoma Highway Patrol trooper Kera Philippi.

``At the request of one of the (FBI) agents, we set up informational check points in the area to make sure all area residents were aware of the crime and to see if they knew of any unusual activity,'' Philippi said.

``He was an occupant of a vehicle. He just wasn't acting right. He was acting suspicious.

``From there, they talked to him and the FBI took him into questioning.''

Fox, 50, of Guthrie, said Underwood lived in the apartment below Jamie and her son-in-law, Curtis Bolin, an auto mechanic. Jamie's mother, Jenny, is a truck driver who is staying in Oklahoma City. The couple separated several years ago, Fox said.

``Jamie was in the apartment below us the whole time,'' said Fox, her voice trembling with emotion. ``The only reason that he couldn't move the body and hide it was because somebody was out there the whole time, either on the balcony smoking or standing in front of the apartment.

``He couldn't take her someplace else and dump her.''

Agents with the Oklahoma State Bureau of Investigation searched Underwood's apartment and were interviewing residents at the complex on Saturday, OSBI spokeswoman Jessica Brown said.

``We collected evidence and will take it to our laboratory for testing,'' Brown said. ``It's the apartment that we're focusing on.''

The manager of the apartment complex, Tim Bayer, told The Oklahoman that Underwood liked to stand outside his apartment and watch children play. He said Underwood didn't have a car of his own and that he kept his apartment clean.

McClain County District Attorney Tim Kuykendall called Jamie's killing one of the most ``heinous and atrocious'' crimes he'd seen in his career as a prosecutor, but would not elaborate.

Tompkins said authorities were sure the body was Jamie's although they were still awaiting confirmation from the medical examiner.

Authorities said they went to Underwood's apartment after a tip from the FBI, one of several law-enforcement agencies that searched for Jamie.

The FBI would not reveal any details about the tip and spokesman Gary Johnson said Saturday that the investigation had been turned over to the OSBI.

The girl was last seen Wednesday afternoon at the library in Purcell, about 40 miles south of Oklahoma City, and she was reported missing that night.

Police waited until Thursday night to issue an Amber Alert because no abduction was witnessed and officials suspected she had run away, Tompkins said.

Even if an alert had been issued sooner, it ``probably wouldn't have helped us recover Jamie,'' said state patrol Lt. Chris West. He wouldn't elaborate.

Fox said the family is distraught, especially Curtis Bolin, who remained under sedation on Saturday.

``His whole life revolved around Jamie,'' Fox said. ``He didn't go out and party. He didn't drink or smoke.

``This has probably destroyed him.''

For her part, Fox said she plans to keep her commitment to sing in the church choir on Easter Sunday and hopes she can bring herself to forgive.

``I'm going to sing in praise of the Savior, and I'm going to sing as a slap in the face to the evil that took her away from us.

``As far as her being lost, she's not lost. We know that we're going to see her again someday. So, tomorrow, I will sing for my Jamie.''