In the recent warrant for Mr. Dulos’s arrest, the police said they believed he was “lying in wait” for Ms. Dulos at her home the morning that she disappeared and that he carried her body out of her home.

The police have not directly implicated Ms. Troconis in Ms. Dulos’s disappearance. After her arrest in June, she gave at least three interviews to investigators, appearing to be cooperative.

In her third interview, on Aug. 13, she admitted to not being truthful in previous conversations and provided information that led to a new evidence-tampering charge against Mr. Dulos: He cleaned up a red Toyota truck believed to have been used in Ms. Dulos’s disappearance, a warrant said.

According to the warrant, Ms. Troconis told the police that on the afternoon that Ms. Dulos, then 50, disappeared, she saw Mr. Dulos cleaning what he said was spilled coffee in the truck. When he handed her a stained rag, it did not smell of coffee, she said.

Under pointed questioning, Ms. Troconis ultimately admitted that she placed one of the stained rags into a black garbage bag similar to the ones later discovered to have been tossed out in Hartford.

Ms. Troconis also told the police that days later, she followed Mr. Dulos to a carwash where he had the Toyota truck detailed and washed, according to the warrant.

Surveillance footage showed her in the passenger seat of another vehicle with Mr. Dulos at a nearby bank where he withdrew cash to pay for the detailing, the warrant said.