Authorities investigating the murder of Yale graduate student Annie Le have focused their efforts on a suspect who failed a lie detector test, sources told ABC News.
Investigators zeroed in on a suspect as the medical examiner positively identified the body found stuffed in a wall in a Yale University lab as the missing grad student. The medical examiner's office listed the cause of death as homicide, but withheld the exact manner in which Le died.
The body was discovered Sunday, the same day that Le was supposed to get married.
The suspect who police are looking at has what appear to be defensive wounds, a key piece of circumstantial evidence. In addition, the suspect, who authorities believe knew Le, failed a lie detector test, sources told ABC News. Sources also told ABC News that bloody clothing removed from the lab contained evidence that links the killer to the crime.
Investigators have been looking at everyone from Yale maintenance people to people who worked in the lab and fellow students.
"We're not believing it's a random act," Officer Joe Avery, a police spokesman, told The Associated Press. He would not provide further details but said no one else is in danger.
A body believed to be Le's was found Sunday evening, stuffed into a wall in the basement of the Amistad Street laboratory where she was last seen Tuesday morning.
Though police have seemingly narrowed in on a suspect, the mood around Yale is still one of sadness and uncertainity. The last on-campus murder was the 1998 stabbing death of 21-year-old Suzanne Jovin. There has been no arrest in her death.
Reached in Germany, Thomas Jovin told ABCNews.com that he did not wish to comment on Le's murder or his daughter's.
New Haven Police Officer Joe Avery told ABCNews.com today that authorities didn't start focusing on the lab until a few days after Le was reported missing. Police were initially unsure, he said, if she had voluntarily disappeared in advance of her wedding, scheduled for Sunday, or if she had been a crime victim.
Once video surviellance cameras revealed Le coming into the building on Tuesday, but not leaving. Search efforts focused on the building. Her body was eventually found, he said, by members of the Connecticut State Police Major Crimes Unit.
Vanessa Flores, Le's former roommate, said she heard the news on the Internet about her friend's body likely being found.
"I had a very tough time just reading the headline," she told "Good Morning America" today. "It was very difficult."
Le, 24, disappeared Tuesday. She had been seen entering the Amistad Street lab around 10 a.m., but none of the cameras caught her leaving. The body was found shortly after 5 p.m. Sunday, shoved into a space in the wall meant to conceal pipes and wiring.
"We did locate the remains of a human. ... We are assuming that it is her at this time," New Haven Assistant Police Chief Peter Reichard told reporters in a brief news conference Sunday.
Flores said she doesn't know why anyone would want to kill her friend, who earlier this year had written a piece for the University Magazine questioning the safety of the New Haven campus.
"The only thing I can possibly think of right now is maybe a psychopath, an anti-social person who, I don't know, maybe got upset about what she wrote back in February about not being safe," she said.
Wedding gifts had been left outside the family home of Le's fiance, Jonathan Widawsky. Their impending nuptials had led some to believe that Le had gotten cold feet and fled.
But Flores said Widawsky was "perfect" for Le.
He's just so wonderful to her. John was so supportive of her, of her dreams," Flores said. "They would talk on the cell phone for hours, and they would just be so connected."
The discovery of the body ends a massive search by state and federal authorities that had expanded to a Connecticut waste-processing facility in Hartford, in addition to the Yale lab, in the hopes of finding clues to her mysterious disappearance.
Using cadaver-sniffing dogs in round-the-clock shifts, FBI agents and state troopers dressed in hazardous-material suits began searching the facility in Hartford Saturday night.
Police scanned blueprints of the lab and brought in blood-sniffing dogs, paying particular attention to the building's basement.
Yale had also offered a $10,000 reward for information leading to Le's whereabouts.
A Prescient Article Written by Le
After the body was found, Yale president Richard Levin wrote in a letter to the university's staff and students:
"It is my tragic duty to report that the body of a female was found in the basement of the Amistad Building late this afternoon. The identity of the woman has not yet been established," Levin's letter said. "Law enforcement officials remain on the scene; this is an active investigation, and we hope it is resolved quickly."
Adding to the intrigue surrounding the case was an article Le wrote for a campus magazine earlier this year about how to stay safe on the Ivy League campus.
The article, titled "Crime and Safety in New Haven," was published in February in the magazine produced by Yale's medical school and compares higher instances of robbery in New Haven to other cities with Ivy League universities.
"In short, New Haven is a city and all cities have their perils," Le wrote. "But with a little street smarts, one can avoid becoming yet another statistic."
Le, who is 4 feet 11 and weighs 90 pounds, had left many of her belongings in the lab when she disappeared.
"She left her pocketbook, her cell phone, everything in the lab," Le's co-worker Debbie Apuzzo said.
Le's Facebook page showed her posing in wedding dresses and smiling with fiance Widawsky, a Columbia University graduate student in physics, whom she described as her best friend.
"He's an amazing kid, just a wonderful, wonderful boy, and he must be heartbroken," Widawsky's friend Linda Matychack said. "I just can't imagine."