Savanah Nicole Soto, a pregnant teenager who disappeared before she was scheduled to be induced, is believed to have been found dead Tuesday following a dayslong search, police said.
Her boyfriend was also found dead, police confirmed Wednesday.
The two bodies were discovered in a vehicle in San Antonio, the city's police chief, Bill McManus, told reporters Tuesday evening, calling the case "very, very perplexing."
"Detectives right now are looking at this as a possible murder, but we don't know for sure," McManus said.
The bodies of an 18-year-old woman and 22-year-old man were found in a parked vehicle, each with a gunshot wound, police said Wednesday. An unborn child was also found deceased, police said.
The medical examiner positively identified the male victim as Matthew Guerra, police said Wednesday night. Police are awaiting positive identification for the female victim.
The victims' cause of death will be confirmed by the medical examiner, police said.
They are believed to have been in the boyfriend's vehicle for three to four days, McManus said.
The vehicle was found on the 5900 block of Danny Kaye Drive in northwest San Antonio, police said. McManus did not know who located it.
Soto, 18, was last seen Friday afternoon in Leon Valley, according to the Texas Department of Public Safety. The agency issued a CLEAR Alert -- used to help law enforcement locate someone in imminent danger or whose disappearance is involuntary -- for Soto on Monday.
The pregnant teen had passed her delivery date, which "caused significant concern among her family members after missing an essential medical appointment," the Leon Valley Police Department said in a press release earlier on Tuesday.
Soto's mother, Gloria Cordova, told San Antonio ABC affiliate KSAT that her daughter was scheduled to be induced at a hospital this past Saturday.
"When I called her all morning she wasn't answering, was going straight to voicemail," Cordova told the station. "We went to the hospital anyways. She was a no-show, and that's when I called the cops."
MORE: Florida mall shooting: Reward up to $10,000 as police hunt for suspectCordova said her daughter's home was clean and had been prepped for the baby's arrival.
"This is not like her," Cordova told KSAT. "She was so excited to have this baby. The house was already baby-ready."
"There's no reason why she would just get up and go off and do that," she added.
Cordova said the family is already reeling after her son, Ethan, died last year. The 15-year-old was fatally shot at his home in San Antonio, police said.
"[Savanah] knows what I went through with Ethan, and I know she doesn't want me to go through this again," the mother told KSAT.
MORE: Search for suspects continues in Christmas Eve Colorado mall shooting that left 1 dead, 3 hurtAmid the search for her daughter, Cordova said she did not know where the father of the baby was either.
"I just want her home," Cordova said. "I'm worried about the baby, if she's even had the baby, if she's in danger."
The Leon Valley Police Department said Tuesday morning that it was actively investigating Soto's disappearance and seeking additional witnesses and information.
The San Antonio Police Department has taken over the investigation.