NEW HAVEN, Conn. -- As police charged a Yale animal lab technician with murder in the death a graduate student who worked in his building, a portrait began to emerge Thursday of an unpleasant stickler for the rules who often clashed with researchers and considered the mice cages his personal fiefdom.

Police charged 24-year-old Raymond Clark III with murder, arresting him at a motel a day after taking hair, fingernail and saliva samples to compare with evidence from the grisly crime scene at Yale's medical school.

Bond was set at $3 million for Clark.

The muscular former high school baseball and football player is charged in the death of 24-year-old Annie Le, a pharmacology doctoral student at Yale who vanished Sept. 8. Her body was discovered five days later -- on her wedding day -- stuffed into a utility compartment behind a wall in the basement of the research building where she and Clark worked.

Authorities offered no details about the crime Thursday. They would not discuss a motive, largely because Clark will not talk to police, and would not disclose the DNA test results or how they connected Clark to the slaying.

The Rev. Dennis Smith, a Le family spokesman, said he was not authorized to comment on the arrest. Smith said he did not know whether Le had ever complained about Clark.

Co-workers told police that Clark was a "control freak" who viewed the lab and its mice as his territory, according to a law enforcement official who spoke to The Associated Press on condition of anonymity.

The investigator also said authorities do not necessarily need to prove a motive because they have an abundance of strong forensic evidence.

As a technician, Clark's duties included cleaning mouse cages and the floors of the lab.

ABC News reported that Clark sent a text message to Le on the day she vanished requesting a meeting to discuss the cleanliness of mouse cages in the research lab.

New Haven Police Chief James Lewis called Le's death a case of workplace violence. He would not elaborate except to say reports that the two had a romantic relationship were untrue.

The Connecticut medical examiner said Wednesday that Le died of "traumatic asphyxiation," which could indicate a choke hold or some other form of suffocation caused by a hand or an object such as a pipe.