BOSTON -- New York police now say they have linked their prime suspect, Darryl Littlejohn, to the murder of Boston student Imette St. Guillen, thanks to blood evidence.

NewsCenter 5's Gail Huff reported that St. Guillen's Mission Hill family is not saying anything about the latest news until police actually make an arrest, but New York's police commissioner said detectives now have DNA evidence in the case that will be presented to a grand jury as early as Monday.

St. Guillen's raped, strangled and suffocated nude body was found dumped in a deserted Brooklyn field on Feb. 25, hours after she was last seen talking to Littlejohn, 41, at a trendy SoHo bar called The Falls where he worked as a bouncer. St. Guillen, 24, was studying criminal justice at the John Jay College of Criminal Justice in Manhattan at the time of her death. She was a Boston Latin grad.

"This is the smoking gun," retired New York City detective Gil Alba said, claiming police have discovered the critical link for which they've been looking.

"This one is physical evidence that puts him with her. Now what can he say? Now, with this evidence, it's certainly him," Alba said.

The DNA match is from blood found on plastic ties that were used to tie St. Guillen's hands behind her back. Similar ties were found in Littlejohn's home.

"Darryl Littlejohn's blood was found on plastic ties that were used to bind Imette's hands behind her back," New York City Police Commissioner Ray Kelly said.

Police said they got a DNA sample from Littlejohn after collecting it from silverware he used when he ate Chinese food detectives provided for him. They also took his DNA from a plastic cup from which he drank soda.

Littlejohn's attorney said he knew nothing of a DNA match with his client until he heard it on television Sunday.

"They played this case out in the media, which puts my client behind the 8 ball right away," attorney Kevin O'Donnell said.

He said he was told nothing about the lab results.

"I want to know who recovered it, how was it recovered, where was it recovered. What was done with it? Who tested it? If it needed to be re-tested, why did it need to be re-tested?" O'Donnell said on Good Morning America.

Carpet threads found on the tape used to wrap St. Guillen's body also matched red carpet threads found in his Jamaica, Queens, home. Also in Littlejohn's home, investigators found the back seat of Littlejohn's van, which had been removed from his vehicle. His cell phone records also place him near where St. Guillen's body was found at the time of her death. Cat hairs found on the blanket used to wrap her body were also a direct match to Littlejohn's cat, police said.

Littlejohn, a convicted criminal with a record that spans two decades, continues to be held in custody on a parole violation. He has not been formally arrested or charged with any crime.