Raymond Clark, the lab technician who police have labeled a person of interest in the murder of Yale grad student Annie Le, has wounds on his chest, arms and back, sources told ABC News.
The deep scratches came to light as the Connecticut medical examiner released Le's cause of death as strangulation, or as it was officially described, "traumatic asphyxia due to neck compression."
Sources also said investigators are finding evidence that the pint-size scientist who weighed only 90 pounds put up a fierce struggle against her attacker.
Blood spatter was found on a laundry cart, and a bead from her necklace was found on the floor of the basement lab where she was killed and stuffed into a wall panel.
Police also found a pair of bloody surgical gloves.
ABC News has also learned that Clark sent a text message to Le early Tuesday, Sept. 8, requesting a meeting to discuss the cleanliness of the the cages of the mice in the research lab.
Le, a 24-year-old Ph.D. candidate, used the mice in her research. Clark, also 24-years-old, is not a student at the university and had more of a custodial role in the lab.
Police were able to track Clark's movements by reviewing the data from his digital key card, which shows he entered the building no fewer than 10 times, including after hours, on the day Le went missing, according to law enforcement sources.
The medical examiner's report came just hours after police took DNA samples from Clark and searched his apartment looking for clues.
Clark was released this morning. Police have not issued a warrant for his arrest.
Clark was taken into custody by police about 10:30 p.m. Tuesday on a warrant that allowed detectives to take DNA samples. Clark cooperated and was released around 3 a.m. today, said New Haven Police Department spokesman Joe Avery.
Police confirmed Wednesday that an additional warrant to search Clark's Ford Mustang was also served.
"He's not under arrest. We can't hold him," Avery said. "He was only made to comply with the warrant."
Law enforcement sources said Clark failed a polygraph test when he was first brought in for questioning.
At a press conference Wednesday evening New Haven Police Chief James Lewis said Clark has retained an attorney and therefore could not be questioned further.
Lewis refused to comment on whether there was a relationship between Clark and Le beyond working together in the same building. He would not speculate as to a potential motive.
The chief would not confirm whether Le had been sexually assaulted.
Clark is being monitored by the police. Authorities continue to question other people in the building, but they have not served search warrants against anyone else.
"We're still in the process. We don't want to be accused of tunnel vision. We're still making sure who was in that building," said Lewis.
Lewis said Clark was handcuffed during the execution of the warrants because investigators were gathering DNA evidence from saliva, hair and fingernails and did not want anything tampering the process.
"We took him into custody to gather evidence from his body and his person," Lewis said.
Police said they have so far gathered 250 pieces of evidence.
Lewis said the arrest hinges now on the physical evidence and securing a DNA match.
"One match of a person at that location, we'd be going for an arrest warrant," he said.
On Wednesday, attorney David Dworski confirmed he was representing Clark.