Savanah Soto and Matthew Guerra
CNN  — 

A 19-year-old and his father have been arrested in connection with the killings of a pregnant Texas teen and her boyfriend after their bodies were found last week in a car in San Antonio, authorities said Wednesday.

Christopher Preciado was arrested on suspicion of capital murder in the deaths of 18-year-old Savanah Soto, who was nine months pregnant, and 22-year-old Matthew Guerra, the San Antonio Police Department said in a news release on Facebook.

Preciado’s father, Ramon Preciado, 53, was arrested on charges of abuse of a corpse, the release said, accused of helping his son “move the bodies.”

CNN is working to determine whether Christopher Preciado and Ramon Preciado have legal representation.

The younger Preciado is being held on $1 million bond, Bexar County court records show. Bond for his father was set at $100,000, with a hearing scheduled for February 6. There was no hearing date listed for Christopher Preciado.

“We do expect more charges to be pending,” San Antonio police Sgt. Washington Moscoso said at a news conference Wednesday night, adding the killings appeared “to be a narcotic-related deal that went bad.”

Detectives would work with the Bexar County District Attorney’s office to determine if there will be “any charges related to the unborn baby,” Moscoso said. The case had been listed as a capital murder “due to the death of an unborn child,” San Antonio police Lt. Michelle Ramos told CNN last week.

From left, Christopher Preciado, 19, and Ramon Preciado, 53.

The bodies of Soto and Guerra were found, each with a gunshot wound, in a car parked near a San Antonio apartment complex on December 26, police had said.

The bodies may have been there for “possibly three or four days,” Police Chief William McManus told reporters last week, describing the crime scene as “very, very perplexing.”

Soto, who was past her delivery date, was reported missing by her family when she missed an essential medical appointment, according to police in Leon Valley, Texas.

Guerra was Soto’s boyfriend, family members told CNN affiliate KSAT.

The arrests came days after San Antonio police asked for the public’s help finding “two persons of interest” seen in surveillance video that captured a pickup truck and the victims’ vehicle driving up to each other in the area where the bodies were found, then driving away.

“One of the key pieces of evidence that we did collect at the scene was Savanah’s cell phone. That was handed over to our technology team, who was able to download some information on there,” Moscoso told reporters Wednesday. Then with the help of federal investigators, “we were able to get enough information, and so that information was given to our detectives today,” Moscoso said.

The information pointed authorities to the possible location of the pickup truck and ultimately to the two suspects’ home, Moscoso said.

“The father answered the door — he knew why the police were there (and) cooperated fully with the investigation,” according to Moscoso.

Father and son were then interrogated by police, and detectives were able to get a warrant signed by a judge, Moscoso said.

This is a developing story and will be updated.