Chicago (CBS) — A Valparaiso teenager pleaded not guilty Monday to killing a teenage couple in a drug deal gone bad, dumping their bodies in the trunk of a car and setting the car on fire.

Connor Kerner, 17, was charged as an adult with two counts of murder in the deaths of 18-year-old Thomas Grill Jr., of Cedar Lake, and 19-year-old Molley Lanham, of St. John. Their bodies were found in southern Porter County after they had been missing for a week.

Thomas Grill Jr. (left) and Molley Lanham (right) were reported missing in northwest Indiana. Police now believe they were killed in a drug deal gone bad. (Source: St. John Police)

Grill and Lanham were last seen alive last Monday. Police initially did not suspect foul play.

Porter County Sheriff’s police said police in St. John and Cedar Lake issued a missing persons’ report about the couple on Tuesday. On Saturday, sheriff’s police received a tip from an anonymous source that Kerner had killed them, placed their bodies in the Honda Civic they had been driving, and set the vehicle and bodies on fire.

According to court documents, a confidential informant said Kerner told him Lanham drove Grill to Kerner’s grandparents’ home in Hebron for a drug deal. The informant said Kerner claimed Grill tried to rob him, so Kerner pulled out his gun and started firing. The first two shots missed. The third hit Grill but did not kill him.

As Grill was on the ground, begging for his life, Kerner allegedly panicked, due to running out of bullets, and beat Grill to death with a pipe wrench.

Connor Kerner is charged with two counts of murder in the deaths of 18-year-old Thomas Grill Jr. and 19-year-old Molley Lanham. (Source: Porter County Sheriff)

Kerner then allegedly showed Grill’s body to Lanham, who had been waiting outside. Police said Kerner told Lanham he would let her go, but would kill her if she told anyone. When she turned to leave, Kerner allegedly shot her in the head.

That night, Kerner allegedly put the victims’ bodies in the trunk of the Honda Civic they had been driving, drove the car to a field in rural Hebron, Indiana, loaded the car with propane tanks, and set the car and the bodies on fire.

Kerner allegedly told the informant “he had done this before and knew how to cover up a murder and get away with it,” according to court documents.

Police said Kerner planned to later rent a U-Haul to pick up the car, and dump it in the Mississippi River.

Police discovered two bodies in a burned Honda Civic on Saturday in Hebron. Although their identities have not been confirmed, police said all evidence points to the bodies being Grill and Lanham.

Kerner was a student at Valparaiso High School. A check of his criminal records shows only moving violations.

Molly Lanham was a recent graduate of Hanover Central High School where she ran track and played soccer. A family spokesperson said,

“Molley was so unapologetically herself. She was spunky, fashionable, and unique in every way imaginable. Molley will be remembered for her love and kindness for all, especially animals.”