The husband of missing nuclear laboratory worker Melissa Casias says he fears for his safety and that of his family after filing for a restraining order against a private investigator.

Mark Casias, whose wife vanished nearly a year ago before her remains were discovered in a remote New Mexico forest, alleges he has been subjected to a campaign of harassment, public accusations and threats linked to the investigation into her disappearance.

The explosive court filing comes just weeks after authorities confirmed that skeletal remains found in the rugged Carson National Forest belonged to Melissa Casias, a 53-year-old employee of Los Alamos National Laboratory.

Her disappearance sparked nationwide attention and fueled intense online speculation.

A judge was scheduled to consider Mark Casias's request for a restraining order against Arizona-based private investigator Thomas McNally, a former homicide detective who has been working with members of Melissa's family as they push for answers about her death.

According to court documents filed in New Mexico's 8th Judicial District Court, Mark Casias claims McNally has engaged in an 'escalating campaign of public harassment, defamation and criminal threats' directed at him and his family.

Melissa Casias disappeared on June 26, 2025, after leaving her home in Ranchos de Taos.

The Los Alamos National Laboratory employee had dropped her husband off at work earlier that day before returning home.

Her disappearance quickly became one of the most closely followed missing-person cases in the Southwest. 

The mystery drew national attention in part because Casias worked at the laboratory founded during the Manhattan Project and long associated with America's nuclear weapons program.

Authorities later found many of her personal belongings still at home, including her vehicle, purse, keys and cell phones.

Family members also reported that both of her phones had been reset to factory settings before she vanished.

Investigators eventually learned that a witness reported seeing Casias walking eastbound along State Road 518 on the afternoon she disappeared. 

There were also unconfirmed reports that she may have entered a vehicle with an unidentified person.

For nearly a year, searches yielded few answers until in late May, a hiker discovered skeletonized human remains in the McGaffey Ridge area of Carson National Forest, roughly six miles from the Casias family home.

New Mexico State Police later confirmed the remains belonged to Melissa Casias.

A handgun was recovered near the body and authorities have not yet announced an official cause or manner of death. 

The New Mexico Office of the Medical Investigator continues to examine the circumstances surrounding the case.

The discovery ended months of uncertainty about Casias's whereabouts but opened an entirely new chapter in the investigation.

McNally, who has publicly maintained that Melissa's disappearance had nothing to do with classified work at Los Alamos National Laboratory, has repeatedly argued that the focus should remain on what happened in her personal life rather than theories involving national security or missing scientists.

'What the attention should be on is that there's a 53-year-old woman who's missing and has a family who love her,' McNally told the Daily Mail in April.

He has also publicly disputed theories linking Casias's disappearance to her employment at the laboratory.

'It's great that the press is getting this story out there because of the Los Alamos stuff, but it has nothing to do with [LANL],' McNally previously told the Daily Mail. 'If you want to tell the story, tell a real story.'

'I want to be emphatic on this point – this is in no way, shape, or form related to her job.'

But Mark Casias now alleges that McNally crossed a line by publicly accusing him of involvement in his wife's death.

According to the restraining order petition, McNally repeatedly accused him of murder, encouraged members of the public to monitor his activities, attempted to contact relatives through blocked phone numbers, contacted his employer and posted personal information online.

Among the statements cited in court filings is a social media post allegedly directed at Casias that read: 'No one is safe, Mark. Confess your sins.'

Another post referenced in the filing criticized Casias after he was reportedly seen at a restaurant having ice cream following the discovery of Melissa's remains.

Mark Casias is asking the court to bar McNally from contacting him or his family, approaching their home or workplace, communicating with his employer, or continuing online posts he alleges are defamatory.

Meanwhile, Melissa's family has vowed to continue seeking answers.

'We fully intend to continue to pursue answers for justice,' relatives said following the discovery of her remains.

Family members have noted that the area where her body was found had previously been searched, while her daughter Sierra Casias has publicly questioned the significance of a handgun found near the remains, saying her mother did not typically carry a firearm.

No arrests have been made and investigators have not named any suspects or persons of interest.