CNN  — 

New court documents filed in the case of a Colorado man suspected of killing his pregnant wife and their two daughters suggest that some of the victims may have been strangled.

Shanann Watts and her daughters, Bella, 4, and Celeste, 3, were reported missing Monday and found dead on Thursday. Watts’ husband, Chris Watts, was arrested in connection with their deaths but has not yet been formally charged.

Chris Watts

His attorneys asked a court Friday to require pathologists doing autopsies on the bodies of his family to swab the little girls’ necks and hands for DNA, court filings show.

In a second motion, obtained by CNN affiliate KDVR, defense attorneys asked the court to compel the coroner’s office to look for DNA under the mother’s fingernails and on her hands.

They also asked the court to allow defense expert Richard Eikelenboom to take swabs from the bodies.

“I have a lot experience taking samples from dead bodies getting good results after strangulation,” Eikelenbloom wrote to the court. “The hands of the children should be sampled as well.”

It is unclear whether a judge ordered the coroner’s officer to swab for DNA.

The first motion, according to documents, was filed 20 minutes before the autopsies were scheduled to begin.

Defense attorneys did not indicate in the court filings what motivated them to make those requests.

Children were found in oil well

Nearly 24 hours before Chris Watts was arrested in the disappearance of his pregnant wife and young daughters in Colorado, he stood outside his house and publicly pleaded for their safe return.

Shanann Watts’ body was found on the property of a petroleum and natural gas exploration company, authorities said. The company said Chris Watts used to work there, but declined to say when his employment ended.

Attorneys for Chris Watts indicated in a court filing that the bodies of the children were in an “oil well filled with crude oil for several days.”

The cause of death for each family member remains pending while medical investigators wait on test results, a news release from the Frederick Police Department said.

Watch Shanann tell Chris about pregnancy

Chris Watts, 33, was arrested on three counts of first-degree murder and three counts of tampering with a deceased human body, a Weld County District Court judge said during Watts’ court appearance on Thursday. Prosecutors have until Monday to formally charge Watts.

He is being held at the Weld County jail, north of Denver.

Authorities have not revealed a possible motive or other details in the case. A judge sealed the arrest affidavit, which might have provided that information.

What Chris Watts told reporter

CNN affiliate KMGH aired video showing Chris Watts’ pickup truck being towed from the family’s home overnight, as well as investigators removing items from the house in garbage bags.

In an interview with KMGH before his arrest, Chris Watts said his wife got home from a business trip about 2 a.m. Monday. The couple lived in Frederick, a town of about 8,600 people around 30 miles north of Denver.

When asked by the reporter whether they argued, Watts said, “We had an emotional conversation, I’ll leave it at that. I just want them back. I just want them to come back.”

Shanann Watts is pictured with her two daughters, Bella and Celeste.

Watts said he left for work about 5:15 a.m. that day and wasn’t concerned when Shanann didn’t respond to his texts and phone calls because she was probably busy with her job, having just returned from being out of town.

But he said he became worried when one of her friends contacted him around noon and said Shanann wasn’t responding to messages.

“I walked in the house and – nothing,” Chris Watts told KMGH. “She wasn’t here. The kids weren’t here.”

“She said she was going to a friend’s house with the kids and that’s the last thing I heard, and that was it. It was very vague,” he told reporters.

FBI involved in case

An unidentified friend told KDVR that she dropped off Shanann Watts at home about 2 a.m. Monday after they returned from a work trip, and watched her go into the house.

The two planned to meet later, but Watts, 34, didn’t answer her phone or show up for a doctor’s appointment, the friend said.

Police said they conducted a welfare check after Watts’ friend called and requested one.

The FBI and the Colorado Bureau of Investigation were involved in the arrest, Frederick police said.

When asked whether other people were involved, Colorado Bureau of Investigation Director John Camper said, “In terms of any danger to the community, we’re not concerned about that at all.”

Brother posts on Facebook

Frankie Rzucek, who is identified on Shanann Watts’ Facebook page as her brother, posted overnight on his page saying he just wanted “to know why.”

“I just want 30 seconds alone with that heartless psychopath. May Satan have mercy on his soul,” Rzucek wrote. “Doesn’t take a genius to know who was suspect.”

Le-Vel, a “health and wellness” company Shanann Watts worked for, according to her public Facebook page, has posted a message regarding Watts and her two daughters.

“Our hearts are broken for the loss of our dear friend Shanann Watts and her children. Shanann was an amazing woman, mother, friend, and overall person. She lit up every room and was a joy to be around. … Shanann and her children will be dearly missed. We honor them on this sorrowful day.”

Anadarko Petroleum Corporation spokeswoman Jennifer Brice said Watts is a former employee, but declined to say when he left the company.

“We are heartbroken by this, and our thoughts and prayers are with the loved ones and friends of the Watts family. We will continue to support law enforcement in its investigation. He is no longer an employee and given that the investigation is ongoing, please direct all questions to law enforcement.”

CNN’s Sheena Jones, Marlena Baldacci, Joe Sutton and Dave Alsup contributed to this report.