As police charged a Yale animal lab technician with murdering 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, who kept his head down and said "Yes, your honor," when asked whether he understood his rights.
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 - 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.
Clark appeared in court with two public defenders who were new to the case. A private-practice attorney who had represented him during the investigation did not attend the hearing and said Thursday he no longer represents Clark. The attorney declined to give a reason.
Public defender Joseph Lopez said he was still reviewing the case and declined to comment.
Co-workers told police that Clark was a "control freak" who viewed the laboratory and its mice as his territory, according to a law enforcement official who spoke to The Associated Press on condition of anonymity because the investigation is ongoing and many details remain sealed.
The official said police are looking into whether Clark's attitude led to a deadly workplace confrontation with Le, who was just 4-foot-11 and 90 pounds. But investigators say that's just a theory at this point.
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.
Le's work involved experiments on mice that were part of research into enzymes that could have implications for treatment of cancer, diabetes and muscular dystrophy.
with CBS News, a medical student who requested anonymity said Clark was quiet but could be controlling.
She was in the same room with Clark just three days after Le's disappearance - the room is just a short distance from where Le's body was found.
"Rooms in the basement are sound proof, so, even if Annie had been screaming nobody would have been able to hear her," she told CBS News correspondent Randall Pinkston.
The New York Times reported that Clark at times grew angry if lab workers did not wear shoe covers. "He would make a big deal of it, instead of just requesting that they wear them," said a researcher who asked not to be identified.
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.
At a news conference Thursday, 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.
"It is important to note that this is not about urban crime, university crime, domestic crime but an issue of workplace violence, which is becoming a growing concern around the country," Lewis said, adding that he would not rule out additional charges.
More from the Crimesider blog on the investigation into Annie Le's murder:
Was Workplace Violence Behind Killing of Yale Student?
Did Clark Force High School Girlfriend to Have Sex?
Yale Suspect's Wedding Web Site Goes Dark
Photos: Who is Raymond Clark III?
Photos: Raymond Clark and Fiancée in Love
Photos: Yale Holds Vigil for Slain Student
Photos: Student Found Dead on Wedding Day
The Connecticut medical examiner said Wednesday that which could indicate a choke hold or some other form of suffocation caused by a hand or an object such as a pipe.
The Hartford Courant reports that swipe cards show Clark and Le were in the same room shortly after 10 a.m. on Sept. 8. Le wasn't seen alive after that, and her card wasn't used again. But Clark swiped into the area where her body was discovered five days later.
Investigators focused on Clark early in the investigation and searched his apartment Tuesday, when they labeled him a person of interest. He remained under constant surveillance after he was released early Wednesday and found a room at the Super 8 motel in Cromwell, Conn.
Police waited until unspecified forensic tests linked Clark to the crime scene before getting a warrant and arresting him about 8 a.m. Tuesday. Details of the warrant remained sealed.
Yale President Richard Levin released a statement shortly after the arrest, saying Clark's employment history raised no suspicions.
"This incident could have happened in any city, in any university, or in any workplace. It says more about the dark side of the human soul than it does about the extent of security measures," Levin said in a message sent to the Yale community.
The family of Le's fiance, Jonathan Widawsky, issued a statement Thursday, thanking people who were involved in preparations for "a wedding that was not to be."
Clark was taken to the New Haven Correctional Center, a high-security state prison for people awaiting trial. His next court date is Oct. 6.
"We share in the grief of the family of Annie Le and are, collectively, doing our best to deal with our tragic loss," said the family's statement, which concluded: "Annie will live in our hearts forever."
More on the Annie Le investigation at CBSNews.com:
Yale Student Suffocated, Coroner Finds
"The Early Show:" Yale 'Unnerved' By Murder
Yale Student's Slaying an Inside Job?
Cops: Yale Student Killing Not Random Act
Tragic Find In Search for Yale Student
In September 2003, when he was a senior at Branford High School, Clark reportedly upset a girlfriend so much that police warned him to stay away from her.
The New Haven Independent reported that when the girl tried to break up with Clark, he attempted to confront her and wrote on her locker.
The girlfriend and her mother told a detective that she had been in a sexual relationship with Clark and that he once forced her to have sex. The relationship continued after that incident, according to the Independent, a news Web site.