(AP) - As police charged a Yale animal labtechnician with murdering a graduate student who worked in hisbuilding, a portrait began to emerge Thursday of an unpleasantstickler for the rules who often clashed with researchers andconsidered 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 andsaliva samples to compare with evidence from the grisly crime sceneat Yale's medical school.

Bond was set at $3 million for Clark, who kept his head down andsaid "Yes, your honor," when asked whether he understood hisrights.

The muscular former high school baseball and football player ischarged in the death of 24-year-old Annie Le, a pharmacologydoctoral student at Yale who vanished Sept. 8. Her body wasdiscovered five days later - her wedding day - stuffed into autility compartment behind a wall in the basement of the researchbuilding where she and Clark worked.

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

Clark appeared in court with two public defenders who were newto the case. A private-practice attorney who had represented himduring the investigation did not attend the hearing and saidThursday he no longer represents Clark. The attorney declined togive a reason.

Co-workers told police that Clark was a "control freak" whoviewed the laboratory and its mice as his territory, according to alaw enforcement official who spoke to The Associated Press oncondition of anonymity because the investigation is ongoing andmany details remain sealed.

The official said police are looking into whether Clark'sattitude led to a deadly workplace confrontation with Le, who wasjust 4-foot-11 and 90 pounds. But investigators say that's just atheory at this point.

The investigator also said authorities do not necessarily needto prove a motive because they have an abundance of strong forensicevidence.

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

At a news conference Thursday, New Haven Police Chief JamesLewis called Le's death a case of workplace violence. He would notelaborate except to say reports that the two had a romanticrelationship were untrue.

Investigators focused on Clark early in the investigation andsearched his apartment Tuesday, when they labeled him a person ofinterest. He remained under constant surveillance after he wasreleased early Wednesday and found a room at the Super 8 motel inCromwell, Conn.

Clark was taken to the New Haven Correctional Center, ahigh-security state prison for people awaiting trial. His nextcourt date is Oct. 6.