Transcript for Estranged husband of missing Connecticut mom arraigned on murder, kidnapping charges
I just want to tell my children that they're constantly on my mind and that I love them and miss them very much. Reporter: For months, dulos was the picture of a man concerned about his estranged family. In the midst of a bitter divorce battle over custody of their children, his wife Jennifer went missing. Yet, as public concern grew over her whereabouts, his position remained. She's alive and well. I wish Jennifer and her family a happy holidays. And I just pray that they give my kids my love and my best wishes. Reporter: His attorney accusing her in the press of staging her disappearance a la the movie "Gone girl" while denying he had nothing to do would it. I never wanted Jennifer out of the way. Even I could get sole custody, I still would not take it, because I wouldn't want my children to have a relationship with their mother. You wanted them. I care about the children. Reporter: But now, seven months after Jennifer was last seen, dulos has been charged with her murder. As you know, Mr. Dulos was arrested today and charged with three counts. Murder, felony murder and kidnapping. Reporter: Dulos arriving in his state police transport. There he is handcuffed in the passenger seat. You can see him right now. After this great length of time, I expected to see a forensic display that was breathtaking. I saw nothing. Reporter: And police now saying he had help. In a shocking twist, his now ex-girlfriend, Michelle tra Coe nis and his attorney. Do you believe they have the evidence to convict you on the murder? It's not exactly clear from the arrest warrant why Melanie has been charged in the conspiracy, but it appears he has given inconsistent statements about his contact with dulos. It also appears he may have been on the phone with dulos when surveillance cameras caught dulos dumping items into trash cans in Hartford. Having three people arrested for the same crime is not strange at all when you look at the conspiracy charge. The charges are that dulos actually committed the murder and that two other people conspired to help in some regard. So it's not uncommon, criminally speaking, for one person to be the primary instrument of death and other people to be accused of helping in some manner. Maybe to help plan. Maybe to help clean up. Reporter: The trio's arrest warrants alleging explicit and horrifying details of Jennifer's final moments. He used as many as four zip ties to incapacitate her. Reporter: Those documents alleging a potential star witness for the prosecution. The family's nanny. The nanny told police that she had a sinking feeling that something had happened to Jennifer dulos and that her estranged husband must have been involved. Please understand that this investigation is still ongoing. Although our goals are to be transparent, we are subject to that gag order. Reporter: The mystery started in the wealthy, tree-lined suburb in Connecticut. It was a Friday morning in late may, almost the end of the academic year when Jennifer dropped off her five children for school. Surveillance cameras show she returned to her rented home around 8:00, then vanished. Hours later, worried friends called the police after she missed several appointments. We love you. And we are doing everything we can to bring you home. Reporter: Her disappearance sparking an intense search, stretching across state lines, making headlines in the national news. New developments in the case of that missing mother of five. Reporter: Drones, k-9 D and a helicopter scoured the area, her vehicle found near a wooded park. Key evidence found inside her rented home. A police affidavit released back in June revealed authorities found multiple stains on the garage, multiple areas of suspected blood splatter and evidence of attempts to clean the crime scene, that affidavit showing that Jennifer was the suspect the victim of a serious, physical assault. And in court documents, Jennifer seemed to fear for her safety, claiming in 2017, I am afraid of my husband. I know that filing for divorce and filing this motion will enrage him. I know he will retaliate by trying to harm me in some way. Dulos strongly denied any threatening behavior, calling his wife incapable of parenting because she allegedly was taking anti-psychotic medications. Suspicion first fell on dulos and his girlfriend, Michelle Troe conis because surveillance cameras caught him dumping item items. They found items that contained Jennifer's DNA. Reporter: Dulos and troconis would be arrested multiple times. We intend to plead not guilty to these charges. It's an exhausting fight. I love my children. They do, but where's the murder charge? Michelle is presumed innocent, and she should be. Reporter: Police released a detailed, 38-page warrant with cell phone data and DNA analysis, showing what police say is a trail of suspicious activity in the days following Jennifer's disappearance, critical details include Troe conis admitting that she had not been truthful during previous questioning. She said she and dulos took a shower together the morning Jennifer disappeared, providing an alibi for him, but she later admitted she did not see him that morning. According to this week's arrest warrant, police say security video shows a man they say is dulos riding a bicycle to Jennifer's home the day she vanished. Police interviewed one of his employees who confirmed that dulos owned a bicycle. And that's important because it puts him at the house. There was no car there that he owns. Reporter: Police alleging dulos was lying in wait. Connecticut state police say it appears he first encountered his estranged wife in their home and used zip tie the. As many as four of them to somehow incapacitate and restrain her. And when police recovered these zip ties, two of them had what appeared to be a blood-like substance on them. Reporter: But now police revealing after they say dulos left the home with Jennifer, someone else arrived. The first person to arrive at Jennifer dulos' home after it appears she had been killed, was the nanny for the five children. And she immediately notices something's wrong. She walked into the house, and the nanny notices that dulos' purse is still there along with her morning cup of tea. When she went to dry the mug after washing it, she noticed there were no paper towels. She had just purchased an entire pack of paper towels, and ten rolls were missing, and the nanny thought to herself what could have gone on in this house? Reporter: Dulos' attorney already mounting his client's defense. What I learn from raiding the warrant is there's no there there. There are reasons to suspect Mr. Dulos, and Mr. Dulos has contended he's not guilty, and we confidently go to trial on that basis. Reporter: None of the suspects have formally entered pleas. For now, the children remain in the care of Jennifer's mother in New York City. And despite these new developments, questions still what exactly happened to Jennifer? For "Nightline," I'm Eva pilgrim in Stanford, Connecticut. Both dulos and troconis are expected to post bond and get out of jail tomorrow. They'll be under house arrest until their trial.
This transcript has been automatically generated and may not be 100% accurate.