Authorities have identified three of the four Detroit women found dead this month in two incidents in Detroit, an investigator with the Wayne County Medical Examiner’s Office said Friday.

Three of the Detroit women have been linked to a website that accepts ads for escort services, police have said.

In the latest case, one of the two women found early Christmas Day in the trunk of a car that had been set afire was identified as Vernithea McCrary, 28, the investigator said.

The second victim remains unidentified, said the investigator, who asked not to be identified because he is not allowed to speak on the record to the news media.

The bodies of two other Detroit women found December 19 have been identified as Demesha Hunt, 24, and Renisha Landers, 23. They were found in the trunk of Landers’ Chrysler 300.

Causes of death for the four women were pending toxicology results, which typically take six to eight weeks to be completed, the investigator said.

The process of identification can be difficult.

“People hear of someone that is discovered that we bring down here and they call down here and inform us that someone is missing,” the investigator said. “They give us a description and then they come down if they can be viewed and are recognizable. If not, we ask them to bring a set of dental records for comparison.”

The deaths are being treated as the work of one person or group of people, Detroit’s police chief said Tuesday.

“At this point, we are working it as one case or one suspect or set of suspects,” Chief Ralph L. Godbee told CNN. “There are too many common links for us not to, at this point, work this as one single investigation.”

Among those links, he said, is the fact that three of the women had placed online ads dealing with “prearranged adult dating services” and posted on backpage.com, Godbee told reporters Monday.

“We felt it is imperative to alert the public that deciding to meet unknown persons via the Internet can be extremely dangerous,” Godbee said.

But a lawyer for womensiteonline.com, Steve Suskin, said it was not clear that his company’s website was involved.

“Our team has already provided the police with detailed information about the ads that the suspect or others posted on numerous web sites. Law enforcement authorities now have evidence that the investigation appears to connect to at least 30 different ads or other postings on at least 15 different websites, separate and distinct from ours,” Suskin said.

“We are not aware of the existence of any evidence that would indicate which of these many sites were used by the suspect to establish contact with his victims.”

Backpage representatives have been cooperating with police, the police chief said.

Postings on the escort section of the website cost $1. Referring to the advertisements on the website as “borderline prostitution,” Godbee said that his priorities lie elsewhere. “Right now, we want to get to the bottom of how these four individuals passed away, and who had a hand in their demise,” he said.