Bodies believed to be those of Christopher Watts’ two young daughters were recovered late Thursday in Colorado, bringing to a tragic close a missing persons’ case that captured the nation’s attention.

Watts, 33, of Frederick, is charged with three counts of first-degree murder and three counts of tampering with physical evidence in the deaths of his wife and children, Weld County Jail records show. He is being held without bail.

Frederick police officials announced Thursday night that they believed they had found the bodies of Bella Watts, 4, and Celeste Watts, 3, though they declined to say where the bodies were found.

High-ranking law enforcement sources told ABC7 in Denver that the little girls' bodies were found inside oil and gas tanks on the property of Anadarko Petroleum Corp., the oil and natural gas exploration company for which Chris Watts worked.

The sources told ABC7 that investigators theorize the girls were placed inside the nearly full tanks to mask the smell of decomposition.

Christopher Watts, left, of Frederick, Colorado, is charged with three counts of first-degree murder and three counts of tampering with physical evidence in connection with the Monday, Aug. 13, 2018, disappearance and deaths of his wife, Shanann Watts, 34, and their daughters, 4-year-old Bella Watts (top right) and 3 -year-old Celeste Watts (bottom right). Shanann Watts was about 15 weeks pregnant when she died.

Credit: Weld County Sheriff's Office, Colorado Bureau of Investigation via AP

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Credit: Weld County Sheriff's Office, Colorado Bureau of Investigation via AP

“While we will not disclose the location as to where these bodies were located, police can say that they were found in close proximity to the other body whom officers strongly believe is (their mother) Shanann’s,” officials said on Facebook.

The body of Watts’ wife, Shanann Watts, was recovered earlier Thursday. John Camper, director of the Colorado Bureau of Investigation, said during a media briefing Thursday afternoon that investigators were “quite certain” the body was that of the 34-year-old woman, who was about 15 weeks pregnant when she and her daughters were reported missing Monday.

Chris Watts made his first court appearance Thursday afternoon, 9News in Denver reported. Weld County District Attorney Michael Rourke told the court that the slayings took place in the family's Frederick home.

Camper said Thursday that Shanann Watts' remains were found on Anadarko property. 9News reported that Anadarko has multiple properties within 15 miles of Frederick.

Anadarko released a statement in which a spokesperson said Watts was fired Wednesday, the day of his arrest, 9News reported.

“We are heartbroken by this, and our thoughts and prayers are with the loved ones and friends of the Watts family,” the statement read. “We will continue to support law enforcement in its investigation.”

Tributes grow outside the home where a pregnant woman and her two daughters lived Thursday, Aug. 16, 2018, in Frederick, Colo. Shanann Watts' husband, Chris Watts, has been charged with murder in her death and the deaths of Bella Watts, 4, and Celeste Watts, 3, who authorities believe were killed Monday, Aug. 13, 2018, in the home. The bodies of the missing woman and children were found Thursday on the property of Chris Watts' former employer.

Credit: AP Photo/David Zalubowski

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Credit: AP Photo/David Zalubowski

Law enforcement officials also expressed sorrow over the homicides.

“This is absolutely the worst possible outcome that any of us could imagine,” Camper said Thursday. “I think our hearts are broken for the town of Fredrick as much as anybody’s.”

Fredrick police officials said they received a call just before 2 p.m. Monday reporting Shanann, Bella and Celeste Watts missing. The report was made by a friend who went to the family's home in the Wyndham Hill subdivision and found no sign of Shanann or the girls.

Chris Watts said in an interview Tuesday with 9News that he saw the woman at the front door, via the home's doorbell camera, and realized his family was missing.

"I said, 'Hey, what's going on?' And she said, 'I can't get ahold of Shanann,'" Watts said. "That's when I was just, like, 'OK, something's not right.'"

He said he, too, had been unable to reach his wife via phone or text message.

See Chris Watts’ entire interview with 9News below.

Shanann Watts’ vehicle, as well as her purse and medication for the children, were all still at the house, authorities said. Police on Tuesday upgraded the missing persons report to an “Endangered Missing Alert” because of the potential medical concerns with the children.

Investigators conducted multiple interviews and officers canvassed the family's neighborhood for witnesses and clues. News of the missing mother and daughters soon went national, and Watts did his interview with 9News on Tuesday, in which he described his family's disappearance as "earth-shattering."

"I don't feel like this is even real right now. It's like a nightmare that I just can't wake up from," Watts told a reporter.

Watts spoke in loving terms of his daughters.

“Celeste, she’s just a bottle of energy,” he said. “I call her ‘Rampage’ because she's got two speeds: go, or she’s sleeping. She’s always the troublemaker, she’s always the one, like, jumping off things. Bella, she’s the more calm, cautious, mothering type, and she’s more like me -- she’s more calm. Celeste has definitely got her mom’s personality, where she’s all gung-ho, ready to go.”

The young father also addressed those who might think he had a hand in his family’s disappearance.

"Everybody's going to have their own opinion on anything like this," Watts said. "I just want people to know that I want my family back. I want them safe and I want them here. This house is not the same."

Less than 24 hours later, Watts was in custody. A law enforcement source told 9News that Watts confessed to killing his wife and children.