The wooded yard looked like an archaeological dig as investigators sifted the soil Monday for more evidence of the seven people Michael Lee Shaver Jr. says he shot, cut up and burned in his bedroom fireplace.

Shaver, who authorities say started talking about the bodies after he was arrested following a failed carjacking, was ordered held Monday on $1 million bail on charges of murder and armed criminal action in connection with one 2001 killing, and more charges could be coming.

A search of the rural property where he lived with his mother has so far turned up five quarter-sized bone fragments.

Click here for FOXNews.com's Crime Content Center

A forensic anthropologist determined Saturday that the remains belonged to two people, said Cass County Sheriff's Capt. Chuck Stocking. He said investigators expect to be at the property for at least a week and might drain a pond and septic pool.

It wasn't immediately clear when Shaver would be arraigned or if he had an attorney, Cass County Cpl. Kevin Tieman said.

According to an affidavit filed with the charges, Shaver told authorities he had bought methamphetamine from the man he is charged with killing in 2001. He said they met at an abandoned trailer in Kansas City, Kan., and Shaver later invited the man to his home for another drug transaction, the affidavit says.

Shaver said he shot the man while he was walking to the back door of the home near Drexel, then took some meth and $200 from the body, dragged it to a wooded area, dismembered it and burned it, according to the affidavit.

At first, Stocking said, he was skeptical of Shaver's claim.

The 33-year-old first mentioned that he knew something about human remains on the property near Drexel, an hour south of Kansas City, when officers arrested him Friday following the carjacking attempt.

Shaver later told investigators that he killed seven men — all between the ages of 20 and 40 and from the Kansas City area — during narcotics transactions so he could take their money and drugs, authorities said.

According to the probable case statement, he said he dismembered the bodies, burned them in the fireplace, then used a hammer to crush the bones. Shaver said he then spread the bone fragments around the back yard.

Stocking didn't ruled out the possibility that Shaver was exaggerating.

"He can say that he killed 50, but we have to prove that he actually did," Stocking said.

The killings are believed to have started about five years ago, about the time Shaver moved into the house.

According to court documents, Shaver was sentenced in 1997 to four years in prison for threatening a Kansas City police officer with a knife.

Neighbor Russ Feeback said people in the rural area noticed a lot of traffic at the house, and often heard the heavily tattooed Shaver yelling.

"Every once in a while there would be a gunshot. I just tried to stay away from him," Feeback said.

Another neighbor, Keith McMeins, said he sometimes heard loud fights between Shaver and his mother.

Tieman confirmed that the owner of the land was trying to evict the people because of a dispute over the home. Tieman also said county officers had been to the property about a dozen times in the last five years, including once on Thursday.

Shaver's mother, Shirley A. Bryson, 53, was arrested Thursday and charged with hindering prosecution, but was released on bail Sunday.