Police have obtained, or are in the process of obtaining, an arrest warrant, the sources said.
Police were in Cromwell, where Clark was staying in the Super 8 motel.
This comes hours after police served two more search warrants Wednesday on their "person of interest" in the slaying of a Yale graduate student.
The warrants were for a red Ford Mustang that suspect Raymond Clark drove and a second warrant for his apartment at 40 Ferry St. in Middletown for items not included in the first search warrant executed Tuesday night.
The state's medical examiner's office confirmed Wednesday that the Yale graduate student, Annie Le, was strangled.
The office of the Chief Medical Examiner termed the cause of death "traumatic asphyxiation due to neck compression."
This confirmation came hours after the man described as “person of interest” in the killing provided police with DNA samples and was released early Wednesday, police said.