Ms. Dombroski said that she had reviewed the camera tapes and believed that Mark was not feeling well because he had sustained a shoulder injury during a rugby match that day. At the bar that night, he “wanted to get going,” she said. He was not in a “celebratory kind of mood,” she said.

Officials believe that there were people in Fort Prospect — where Mr. Dombroski’s body was found at 4 p.m. — just before the discovery, Mr. Field-Lament said. “We’d like them to come forward and help us.”

The police want every detail, he said, “no matter how insignificant it may seem to you.”

A forensic pathologist from overseas is expected to conduct the autopsy on Wednesday, Mr. Field-Lament said. But until those results are available, Mr. Field-Lament said he would not comment on how Mr. Dombroski may have died. He did say, however, that contrary to speculation on social media, Mr. Dombroski had not been bound or tied up. He also still had his wallet and cellphone.

Asked about speculation that Mr. Dombroski may have been in a fight at the bar, or that he went to Fort Prospect to meet someone, Mr. Field-Lament asked that anyone making such claims contact the police. “We all want to get to the bottom of what happened to Mark,” he said.

Mr. Field-Lament confirmed that the F.B.I. had been involved since Sunday because Mr. Dombroski’s family has “a connection” to a former director of the F.B.I., but he did not identify the director. He added that the agency would have gotten involved anyway as part of the Bermuda Police Service’s protocol.

In a statement, St. Joseph’s University said the school’s community was “heartbroken” and offered “deepest sympathies” to Mr. Dombroski’s family and others close to him.

On Facebook, the school’s rugby team said it was “terribly saddened by the loss,” and called Mr. Dombroski a “true champion of the game.”