Kelsey Smith's cause of death was strangulation and there is also evidence of a struggle as she tried to fend off her abductor and eventual killer, FOX News has learned.

A high-ranking law enforcement source told FOX News that there is also evidence the 18-year-old abducted last Saturday was stalked. Video surveillance evidence from that day — the day she was abducted from a Target Parking lot in Overland, Kan. — shows the suspect walking out of Target four-and-a-half minutes ahead of Smith. He then directly passed her car and waited for her to reach her car before running over and forcing her into her car around 7:10 p.m.

Edwin R. Hall was charged Thursday with first-degree murder and aggravated kidnapping in Smith's death. Prosecutors said they would consider seeking the death penalty against Hall. His bond is set at $5 million.

"If we believe the crime is severe enough, and we do in this case, we will go to the jurisdiction that provides the most severe penalty," said Phill Kline, Johnson County district attorney. "The discussions continue almost around the clock."

Many of those discussions have been with Eric Melgren, U.S. attorney for the District of Kansas, who said Thursday it is too soon to tell whether federal prosecutors will get involved.

"Phill has called me about the case several times and I have told him to let me know if there was anything we can do to help," Melgren said.

Kline's office said Friday that Smith was strangled with a ligature, although spokesman Brian Burgess would not say exactly what was used.

Hall's attorney, Paul Cramm, did not immediately return a call seeking comment. Cramm filed notice with the court Friday that he would be representing Hall and requested prosecutors' evidence against his client.

Investigators said they believe Hall is the same man whose blurry image shows up in the store's surveillance video, and whose Chevrolet pickup is seen pulling into the parking lot soon after Smith parked her car there.

Investigators still not sure if Smith was killed in Kansas or in Missouri. Search teams found her body just across the Kansas border near a lake in Missouri on Wednesday — about 20 miles from where she was abducted. They have not yet announced the cause of death.

The law enforcement source would not say how Smith was restrained to get her to Missouri. When asked by FOX News whether law enforcement was looking at possible accomplices, and whether Hall had help, the source said "not at this time," but that "I wouldn't rule it out" that he did have help.

The source said Hall was familiar with the area where Smith's body was left. FOX News had earlier reported that the suspect in Smith's death lived several miles away from the area in which Smith was found.

The source also would not reveal whether Hall had a juvenile criminal record.

Meanwhile, on his page on the popular Internet networking site MySpace.com, a man who calls himself "Jack" considers himself a "Sweet Troubled Soul." "Jack" says he is interested in "eating small children and harming small animals."

And he bears a striking resemblance to the 26-year-old Hall.

On the MySpace page, whose existence was first reported by someone who posted a link to it on The Kansas City Star's crime blog, the man says his favorite movies are "anything that pushes the envalope, A clockwork Orange, Srangeland and lets not forget horror movies!!!! yea scary (or cheesy)like."

He uses only the name "Jack," by which Hall is known to neighbors. The person on the MySpace page also uses the same age and location as Hall, and a person with the same name as his wife, Aletha, has a page linked to "Jack's" profile.

In a photo on the page, the man is posing with a young boy. Neighbors said Hall and his wife have a 4-year-old son.

The Associated Press also reported Friday that Hall was convicted 11 years ago of threatening his sister at knifepoint.

According to court records obtained by the AP, a judge convicted Hall after he pleaded no contest in May 1996 and removed him from his adoptive home. Hall was then placed in state custody.

His adoptive parents — Carol and Don Hall of Emporia — didn't immediately return a call placed by the AP. But Carol Hall told The Emporia Gazette that Edwin did something when he was 15 that made the couple feel he was a danger to the family.

"That was the last time he was in our home," Carol Hall told The Gazette about the incident that occurred when Edwin was 15. The Halls hoped then that someone would be able "to get him the help that he needed."

Hall was being held at a Johnson County jail in Gardner, and appeared in court Thursday via a video feed looking tired and downcast. He spoke briefly, waiving reading of the charges until he could hire his own attorney. His next appearance was scheduled for June 14.

Smith's parents, Greg and Missey Smith, attended the brief hearing, accompanied by Kline. Missey Smith told CNN's Nancy Grace on Thursday night that she watched the hearing "because he was there and she wasn't."

"And I know — she always told me, Mom, I've got your back, so I had to be there to have hers," she said.

If convicted, Hall faces a minimum sentence of 25 years to life in prison for the murder charge and more than 12 years for aggravated kidnapping, Kline said. Authorities have not said how or where Smith was killed.

Kline said it was unclear if the case would be tried in state or federal court. But he said the death penalty would be a possibility in either jurisdiction.

Smith's sister, Stevie Hockersmith, 23, and several supporters also attended the hearing. Hockersmith left without speaking to reporters.

Overland Park Police Chief John Douglass said there was no evidence that Hall and Smith knew each other. He and Kline both have declined to offer a motive for the attack.

Shortly after Kelsey's body was found Wednesday in a wooded area about 20 miles east of the Target store, detectives were talking with Hall. A tip from the public led them to Hall, who has been living with his wife, Aletha, and 4-year-old son in Olathe, a Kansas City suburb.

Their next-door-neighbor, Cameron Migues, 30, said he and his wife laughed when they noticed a similarity between Hall and the man pictured on the surveillance video. But that changed after the video of the truck was released.

"We put two and two together," said Migues, who called a police hot line Wednesday morning.

One day earlier, he said Hall's son had been in his backyard playing with Migues' 3-year-old son. Migues said he hasn't seen Hall's wife or son since then.

Neighbor Harold Barry, 50, said he was surprised when he heard Hall had been arrested. He also said Hall seemed especially close to his son.

"He loved his son his so much," Barry said. "He had his small kid in that truck every time I saw him."

FOX News' Jeff Goldblatt and The Associated Press contributed to this report.

MySpace is owned by News Corp., the parent company of FOXNews.com.