Almost from the moment Jennifer Dulos went missing from her home in an affluent Connecticut suburb on May 24, detectives have kept their focus on the estranged husband with whom she was locked in a bitter divorce battle.

As the police investigated, determining that Ms. Dulos had been the victim of a serious physical attack, the evidence against the husband, Fotis Dulos, appeared to mount. They traced his suspicious movement via cellphone records, found his blood in her home and uncovered footage of him dumping bloody evidence in trash cans.

Still, even as Mr. Dulos was arrested and charged twice in the case, the police never accused him of attacking Ms. Dulos.

Then, on Tuesday, seven months after their investigation began, the police descended onto Mr. Dulos’s house, took him away in handcuffs and charged him with murdering his wife.