Police investigating the murder of a Yale graduate student are still collecting evidence, including a car they towed from the motel where the suspected killer was arrested.

Police wouldn't confirm who owns the Ford Taurus they towed Friday night from the Super 8 motel in Cromwell, Conn. The father of Raymond Clark III, the Yale lab technician charged with the murder of Annie Le, checked into the motel before his son was arrested Thursday.

A state trooper who took part in the seizure confirmed that it was related to Clark's arrest. It's not clear if the suspect's father is still staying at the Super 8, and police did not enter the motel.

New Haven police spokesman Joe Avery said he knew nothing about the seizure. Cromwell police referred questions to the New Haven police department.

Clark's parents, Raymond John Clark Jr. and Diane Clark, are separated, according to a person familiar with the family who spoke on the condition of anonymity because of the nature of the charges.

New Haven Police Chief James Lewis told The Associated Press in a telephone interview Friday that the investigation was continuing, although they didn't expect more arrests. Lewis said authorities may never know the motive for the killing of Le, whose body was found hidden behind a wall on what should have been her wedding day.

"The only person who knows the motive is the suspect," Lewis said. "It's true in many cases. You never know absolutely unless the person confesses, and in this case it's too early to tell."

Clark, a technician in the lab where Le conducted research, was arrested a day after authorities took DNA samples from him to compare with evidence from the crime scene.

Clark's bond was set at $3 million, and he did not enter a plea.

A telephone message seeking comment from the public defenders' office, which is representing Clark, was not immediately returned Saturday.

A law enforcement official who talked to the AP on condition of anonymity because the investigation was ongoing and many details remained sealed said co-workers called Clark a "control freak" who was territorial about the mice whose cages he cleaned. Authorities are investigating whether that attitude might have set off a clash between Clark and Le.

Clark tried to hide evidence even as investigators worked in the basement lab around him, authorities said, then coolly played a softball game on the day Le's body was found stuffed inside a nearby wall.

An investigator observed Clark trying to hide cleaning equipment that contained blood splatters as teams probed the disappearance of Le, who was 24, according to a law enforcement official familiar with the investigation who spoke to The Hartford Courant.

Investigators have records of Clark, also 24, cleaning areas that Le was in before she was reported missing Sept. 8, the official told the Courant, speaking on condition of anonymity.

But despite Clark's efforts, investigators found DNA of both the suspect and victim in the ceiling and in the wall recess where Le's body was hidden, the official told the paper. New Haven police wouldn't confirm that information to the AP.

The body of Le, a pharmacology student from Placerville, Calif., was recovered Sunday, the day she was to get married on New York's Long Island.

Prosecutors may face difficult questions in Clark's trial about why they didn't restrict access to the lab after Le was reported missing, legal experts said. Le disappeared on a Tuesday, and authorities didn't close it until the weekend.

"If a jury is looking for something to grab onto, then this could be something for them to grab onto," said Hugh Keefe, a top state defense attorney.

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, while Clark's technician job involved cleaning floors and mouse cages.

Ann Turner, executive director of the American Association for Laboratory Animal Science, acknowledges "there is a gulf" between technicians and the researchers they interact with, but said a gap in education levels shouldn't necessarily lead to tension.

"If there is a culture of trust and a culture of respect, the researchers will respect the animal care technicians, and vice versa," Turner said.

A memorial service for Le is planned at the Huntington, N.Y., temple her fiance's family attends between the high holidays of Rosh Hashanah, beginning sundown Friday, and Yom Kippur on Sept. 28, cantor Sandra Sherry said.

The family of fiance Jonathan Widawsky, a graduate student at Columbia University, had already announced it would not attend services "for the foreseeable future" to ease things for the synagogue, Sherry said.

Clark is jailed in Suffield, about 20 miles north of Hartford. His next scheduled court date is Oct. 6.