An animal research technician charged with killing a Yale graduate student raised suspicions when he began scrubbing floors after the crime and tried to move a box of bloody wipes from the view of an investigator, according to an arrest warrant released Friday.
The body of 24-year-old Annie Le was found stuffed behind a Yale research lab wall in September. An autopsy determined she was strangled.
Authorities say in the warrant that a green-ink pen found under Le's body had her blood on it, as well as DNA from suspect Raymond Clark III, on its cap. Police have said Clark signed into the secure building with a green pen on Sept. 8, the day Le disappeared.
The warrant says DNA from both Le and Clark was on a bloody sock found hidden in a ceiling.
The document also says Clark moved a box of wipes to hide blood spatters on it. Clark had a scratch on his face and left biceps that he said came from a cat, according to the affidavit.
Joe Lopez, Clark's public defender, declined to comment Friday.
Clark, 24, is charged with murder. Le vanished Sept. 8 from the Yale medical school research building where she and Clark worked, and her body was found five days later, on what was to be her wedding day. She was wearing surgical gloves with her left thumb exposed, according to the affidavit.
Clark has not yet entered a plea, but his attorney has said he will plead not guilty.
Clark said he knew Le for at least four months and did not socialize with her. He told police Le left the building 15 minutes before him carrying her notebook and two bags of mouse food.
The warrant, which does not offer a motive, describes a bloody crime scene and Clark's efforts to scrub floors.
Two days after Le disappeared, a graduate student showed a Yale police officer a box of "wipe alls" on a cart in a lab that had what appeared to be blood splattered on it. The officer watched Clark move the box of wipes and turn the box so that the bloody spots were not visible, authorities said.
"Once Clark moved the box of wipes, he then leaned up against the cart and made small talk" with the officer, the affidavit states.
The blood spatter on the wipes matched the victim's DNA, authorities said.
Clark later came back into the room and began scrubbing the floor with SOS pads and cleaning solution even though the floor appeared to be clean, according to the affidavit. He was also spotted "on the floor" inside Le's lab scrubbing the floor under a sink with a brush or cleansing pad, according to the affidavit.
Investigators uncovered "a possible medium velocity blood-like spray pattern" on the wall that tested positive for blood and apparent efforts to clean the blood off the wall.
The blood at the scene suggests there was a struggle, experts said, noting Clark's scratches and the possible damage to Le's glove.
"I think there is a big likelihood of a struggle," said forensic pathologist Michael Baden, who has been an expert witness in cases involving John Belushi and O.J. Simpson.
A victim can also cough up blood when being strangled, Baden said. Some of the blood could also be from the body being stuffed in the wall and deteriorating.
Authorities said Clark changed his clothes at least once when the FBI was processing the scene, citing video surveillance of the building.
Authorities said they also found in the building a pair of work boots labeled "Ray-C" that had blood-like stains on them, and a hospital scrub shirt with blood-like stains that was similar to the shirt Clark wore.
Le entered her lab, known as G13, at 10:11 a.m. Sept. 8. Clark's card shows he accessed the victim's lab at about 10:40 a.m. and again at 11:04 a.m. and no other locations for 46 minutes.
Clark's key card was the only one used to access a room where blood was found after Le entered the building, according to the affidavit.
"Clark's movements after this entry are considered uncharacteristic for his normal movements throughout his work day," the affidavit states.
He used his key card to gain entry into the room where Le worked and another room 55 times from 10:40 a.m. to 3:45 p.m. the day Le disappeared, according to the affidavit.
A judge last week ordered portions of the court documents to be unsealed.