BOULDER, Colo. -- A suspected serial killer who has been linked to four murders was charged Tuesday in connection to those murders.

Scott Kimball was charged with two counts of second-degree murder. Kimball, 42, has been under investigation by the FBI since last year in the disappearance of his 60-year-old uncle Terry Kimball, Jennifer Marcum, Kaysi McLeod and Leann Emrie.

Kimball disappeared in 2004 and the women disappeared in 2003.

Even though there are four victims, there are only two murder charges, as part of a plea agreement that required Kimball to lead authorities to the remains of his victims, according to the arrest affidavit.

A hearing is scheduled Thursday at the Boulder County Justice Center. Authorities were planning to hold a news conference after the hearing, where the district attorney's office said it would further explain the charges.

According to the arrest affidavit, the first murder charge is for Terry Kimball. The second murder charge is for Marcum, McLeod, and Emry.

Emry's body was found in eastern Utah in March, and 19-year-old Kaysi McLeod's remains were found in northwest Colorado in September.

Kimball, who was already being held at a state prison, was arrested and placed in Boulder County Jail. He is being held there in lieu of a $2 million bail.

Details Of Arrest

When Kimball was arrested in June 2003 for a check fraud violation, he told an FBI and DEA Agents that Jason Price -- a friend of Marcum's boyfriend -- had strangled Marcum and placed her body in a creek bed near Rifle, Colo. Price had told agents that he and Marcum's father suspected Kimball was involved in Marcum's disappearance, according to the arrest affidavit.

Kimball's ex-wife, Lori McLeold, told FBI agents in April 2007 that while she was traveling with Kimball from Denver to Las Vegas sometime in 2003, they were passing through Rifle, and Kimball pointed to the Rifle road sign and told her, "That's where Jennifer's body is." She said Kimball told her he worked for the FBI and was involved in a case involving Marcum's murder. Kimball said that Jason Price had killed Marcum and was willing to pay Kimball to remove her breast implants and IUD so she would not be identified.

Kimball was sentenced in December 2008 in Boulder County to 48 years in prison on a theft charge. His sentence was as severe as it was because he is a repeat offender. He was also sentenced in June to more than five years in prison on a weapons conviction.

Following the sentencing in Boulder, FBI agents met with Kimball, his defense attorneys, Boulder prosecutors, and Judge James C. Klein, where he signed a "memorandum of understanding." That document required Kimball to lead law enforcement to the remains of Marcum, Emry, and Kimball. McLeod's remains had been previously recovered without any assistance from Kimball.

According to that agreement, after all the remains were recovered, Kimball would plead guilty to one count of second-degree murder in Boulder County, but would be immune from further prosecution for these murders.

Upon signing the agreement, Kimball said that the remains of Emry and Marcum were within 15 miles of each other in Grand County, Utah. He said that the remains were in the Sulphur Wash area, approximately 15 to 20 miles north of Interstate 70, near exit 225. Kimball later told the FBI that Terry Kimball's remains were located close to Vail Pass in Eagle County.

Emry, McLeod and Kimball's remains wer found, but Marcum's body was never found where he said he buried it.

Kimball later told fellow prisoners that he was "flimflamming" the FBI, according to the arrest affidavit. An inmate said Kimball told him that "he tried to draw the trip in Utah out as long as he could ... while making a show of trying to find one of the bodies."

"Kimball believes this entire process is a gamevand that Kimball is out to prove that he is smarter than the FBI," an inmate told the FBI.

The victims' families have been waiting for years for answers, and for Kimball to face justice. However, because he is a known liar and con-artist, many of the victims' families said they won't believe that Kimball will plead guilty to the charges until they see it for themselves.