Hatfield filed the complaint for wrongful death and loss of consortium on Monday, June 29, in District Court in Durango.
The complaint said their son, Dylan Redwine, was visiting his father on a court-ordered visit on Nov. 18, 2012, when he disappeared. A massive search ensued, involving community members and local, state and federal investigators. On June 27, 2013, some of Dylan's remains were found approximately three miles from Redwine's home in Vallectio.
A parent in Colorado has the duty to provide proper parental care for a child, the lawsuit states. Mark Redwine breached that duty "when his conduct resulted in the death of their son, Dylan Redwine," the suit stated.
It continues, "the death of Dylan Redwine was the proximated and direct result of the negligence of defendant."
Hatfield also has suffered the loss of consortium with her son and suffered damages from that, the suit stated.
In the lawsuit, Hatfield asks that she be compensated for damages, costs and fees, and she also requested a 12-member jury if the suit should go to trial.
The criminal investigation into Redwine's disappearance also is continuing, according to Lt. Dan Bender, a spokesman for the La Plata County Sheriff's Office.
"I have no new information to release at this time," Bender wrote in an email response to a request for an update on the case. "However, there are several activities that have taken place recently and investigators are putting a lot of effort forward and planning additional actions in the coming weeks."
Dylan Redwine, who was 13 when he disappeared, was on a court-ordered visit with his father for Thanksgiving in 2012. Mark Redwine lives on County Road 500 north of Vallecito. Dylan was raised in Bayfield and had moved that summer with his mother to Monument, near Colorado Springs. Law enforcement confirmed that Mark Redwine picked up his son at the La Plata County Airport on the evening of Nov. 18, they went to Wal-Mart and McDonald's in Durango, and that Dylan was at his father's house that evening. He texted some friends in Bayfield that night and made arrangements to meet with them the next day. The next morning, Mark Redwine told investigators he had to do some errands in Durango, and his son wouldn't wake up, so he left him sleeping on the couch. Redwine said when he returned that afternoon, Dylan was not home. He contacted his son's friends, who said they hadn't seen him, then he texted his ex-wife, asking if she had heard from home. She contacted the Bayfield Marshal's Office.
Hatfield, fiancee Mike Hall and her eldest son, Cory Redwine, then left the Front Range for Bayfield and began searching for Dylan, joined by family friends and numerous community volunteers.
Law enforcement joined in a few days later. At the heighth of the search, local police and sheriff's agencies, the Colorado Bureau of Investigation and the Federal Bureau of Investigation were involved.
No trace of him was ever found until some of his remains, reportedly bones from his foot, were discovered 18 months later by police and volunteers searching Middle Mountain. They were often on their hands and knees and using ropes to climb in the steep terrain.
Hatfield, who now uses her maiden name, previously blamed her ex-husband for their son's death.
In November of 2013, before a memorial service for her son was held at Pine Valley Church, she said she thought Mark Redwine had killed Dylan.
"Yes, I always have from day one, when he was missing," she said in an interview with the Times. "Those who know me, who knew Mark, who knew my boys, knew that as well."
The complaint was filed by Amber Harrison of Durango, who has been Hatfield's attorney since 2008 and handled her divorce.
"I cannot comment on any other specific details, other than those in her complaint," Harrison said. But if more information becomes available from investigators, "we will certainly be amending or modifying the complaint."
Reached on his cell phone on Wednesday afternoon, Mark Redwine said he had not heard about the lawsuit.
"Good luck with that," he said. "We'll all see how it turns out for her."
Redwine said he was not in Vallecito, but declined to say where he was.
"Don't bother asking me, and I have nothing more to say to you," he said before hanging up. "Have a nice day."