'Master manipulator': Suspected murderer using disguises, multiple identities while on run

Investigators are now offering $16,000 for information leading to the arrest of Isabelle Johnson, a suspected murderer who authorities say has been using multiple disguises and identities.

Johnson, 38, has been charged with the murder of 43-year-old Jason Christopher Coulthart.

Coulthart was found dead in a shallow grave last month in Florida after he had gone missing in May, according to the Walton County Sheriff's Office.

Investigators say Johnson is using multiple identities to evade authorities, calling her a "master manipulator."

"These are the faces of a woman wanted for murder. Look closely. She disguises herself well. She's cunning. A master manipulator," the sheriff's office said in a statement.

Johnson may have also "changed her appearance in an effort to evade capture," the sheriff's office said.

Emerald Coast Crime Stoppers and the Florida Sheriff's Association are offering $11,000 for information leading to her arrest. The U.S. Marshals Task Force is also offering $5,000 for information that leads to her arrest.

Coulthart was reported missing on May 24 after he was last seen leaving the College Condominiums complex in Florida, according to the sheriff's office.

Unidentified remains were found on a Freeport, Florida, property on June 25 -- after investigators were able to identify where Coulthart's body had been buried, according to the sheriff's office.

A DNA match confirmed the remains were Coulthart's earlier this month, the sheriff's office said.

Five others have been arrested and charged in connection with the murder, including two people accused of aiding Johnson evade investigators, the sheriff's office said.

Johnson is described as a white female, approximately 5 feet 3 inches tall and 120 pounds, with brown hair and hazel eyes.

Earlier this month, investigators warned that Johnson may be using multiple identities and is known to use several aliases, including Harley, Jessica Elaine Bowman, Jessica Elaine Thrush, Jessica Dowdy and others, according to the sheriff's office.

Johnson is considered dangerous, and the public has been warned not to approach her if she is spotted, the sheriff's office said.

Anyone with information on Johnson's whereabouts is asked to contact the Walton County Sheriff's Office at (850) 8928111. Anonymous tips may be submitted through Emerald Coast Crime Stoppers at 850863TIPS (8477). A cash reward may be available for information leading to her location and arrest.