SAN ANTONIO (AP) — A father and son in Texas have been charged in the killings of an 18-year-old pregnant woman who disappeared before Christmas and her boyfriend, who authorities say were fatally shot in the head before their bodies were moved and discovered days later in a car.

The arrests Wednesday night came more than a week after the bodies of Savanah Nicole Soto, 18, and Matthew Guerra, 22, were found in the parking lot of a San Antonio apartment complex, a crime scene that the city’s police chief originally described as “very, very perplexing.”

San Antonio police Sergeant Washington Moscoso told reporters their deaths appeared to be the result of a drug deal but did not elaborate.

Soto’s family has said she was overdue to deliver her baby and had been scheduled to have an induced labour when she went missing the weekend before Christmas. Moscoso said investigators now believe the couple were killed on December 21, meaning they had been dead for several days before police found them in Guerra’s car the day after Christmas.

The killings have drawn attention beyond Texas and Moscoso said “misinformation” about the case had taken off on social media.

“These two individuals are the only suspects that we were looking for,” he said.

Police said Christopher Preciado, 19, was charged with capital murder and his father, Ramon Preciado, 53, was charged with abuse of a corpse for allegedly helping his son move the couple’s bodies. Online records for the Bexar County magistrate early Thursday did not indicate whether either man had attorneys and San Antonio police did not immediately respond to phone and email messages.

As he was placed in a patrol car late Wednesday night, Ramon Preciado was asked by reporters whether he had remorse.

“Aren’t you sorry for lying about what you’re saying? You don’t even know what’s going on. You just make stuff up like always,” Preciado said.

His son did not comment as police escorted him to a separate vehicle.

Moscoso said prosecutors may pursue more charges against the men, whom he described as the only suspects in the killings. He said information on Savanah Soto’s cellphone that was found in the car led them to another vehicle that was seen on surveillance footage, which authorities publicly released last week in hopes that someone would recognise the people in the video.

That vehicle led police to a house where they found the father and son. He said Ramon Preciado answered the door and cooperated with the investigation.

“He knew why the police were there,” Moscoso said.

The Bexar County Medical Examiner’s Office had ruled both deaths homicides caused by gunshot wounds to the head. Moscoso did not specify where the killing took place before the couple was moved to the apartment complex.

Soto had been scheduled to have an induced labour at a hospital the weekend before Christmas, her family told KENS-TV. But her mother said she got no answer earlier when she knocked on the door of Soto’s apartment in the suburb of Leon Valley.

The family spent Christmas night searching the area and Leon Valley police issued a missing-person alert.