A 22-year-old drug dealer and a teenager strangled a woman -- stealing her car and cellphone to swap for drugs -- then hid the body on swampy property on the outskirts of Cloquet, according to charges.

Michael W. Siewert and Joseph A. Yellow, 17, both of Duluth, were charged Thursday in Carlton County District Court with second-degree murder in the death of Cristyna L. Watson, 25, of Floodwood, Minn.

Siewert drove Watson's car to the Twin Cities, where he traded it and the phone for illicit drugs, according to the criminal complaint against him.

The body of Watson, who had not been seen by relatives since Sept. 8, was found Oct. 4. She had been hit in the head with a hammer and strangled before her body was hidden in swampy, wooded property owned by a co-defendant, according to the complaint against Siewert. Yellow has been charged in a juvenile petition.

The two defendants knew Watson "as part of their drug-trafficking activities" and plotted the robbery and attack, the complaint against Siewert says.

Also arrested and charged as accomplices after the fact were Alyssa Rae Peterson, 24, of Cloquet, Siewert's girlfriend, and Clifford James Thompson, 56, who owns and lives on the property where Watson's body was found.

Siewert remains jailed in lieu of $500,000 bail. Peterson and Thompson are being held in lieu of $100,000 bail each. Yellow is being detained without bail.

According to the charges against the four:

Cloquet police were investigating drug dealing in early October, leading to Peterson telling authorities that she knew something about Native Mob gang activity and Watson's disappearance. Authorities knew that Siewert, Peterson's boyfriend, was a Native Mob member.

Sometime between Sept. 12 and 14, Watson was struck on the head with a hammer by Siewert, then strangled by both Siewert and Yellow.

Based on information from Peterson, authorities used cadaver dogs to find Watson's body on Thompson's property.

Yellow told investigators that Siewert hit Watson with the hammer and both participated in strangling her before the two of them hid the body.

Thompson allowed Siewert to stash drugs at his home, and he let Siewert and Yellow hide out at his property after Watson's death. Thompson also used a shovel to help the two hide or conceal evidence connected to the killing. Thompson also helped burn items linked to the crime.

Siewert was arrested on Oct. 4, the day Watson's body was discovered, in connection with charges that he shot a man in the foot in a gang-related crime. Her car was left near St. Paul.

Peterson is accused of concealing evidence, namely having Watson's cellphone at one point, and helping Siewert evade arrest.

Paul Walsh • 612-673-4482