CHARLOTTESVILLE, Va. >> Virginia police aren’t saying much at all about their evidence against a suspect in the disappearance of a University of Virginia student, but they seem to be working systematically to link his DNA to an expanding circle of attacks on women, a criminal defense expert suggested Tuesday.

Between searches of Jesse Leroy Matthew Jr.’s car and apartment and his arrest on a charge of abducting Hannah Graham last week, police had ample opportunity to obtain genetic evidence connecting him to multiple attacks, said Steve Benjamin, past president of the National Association of Criminal Defense Lawyers.

The Virginia State Police announced Monday that the Matthew’s arrest had provided a “forensic link” to the unsolved 2009 slaying of Morgan Harrington, a 20-year-old whose remains were found in a hayfield three months after she disappeared from a Metallica concert on the Charlottesville campus.

The FBI said in 2012 that DNA evidence showed that Harrington’s killer also was responsible for a 2005 rape in northern Virginia, so Matthew could be linked to that assault as well, although City of Fairfax police declined to comment, citing their ongoing investigation.

Benjamin said Sept. 19 searches of Matthew’s car and home would have been opportunities to obtain DNA evidence — perhaps from saliva on a toothbrush or dirty cup — as a preliminary step that could establish probable cause to obtain a search warrant for a more definitive cheek swab.

“If you’re going to rely on a DNA match (at trial), police are going to obtain what they call a direct reference sample,” Benjamin said. “Anything else is helpful, but not as probative.”

Matthew showed up at the Charlottesville police station the day after the search and asked to see a lawyer. Benjamin said police could have asked Matthew to voluntarily submit to a cheek swab at that time, perhaps suggesting they were looking to exclude him as a suspect — a common police tactic. It would take only an afternoon to obtain the DNA profile and run it through a databank to link it to other cases, Benjamin said.

The only thing police have said about the visit to the police station, though, is that Matthew sped away from officers who had him under surveillance. Authorities didn’t see him again until a deputy sheriff arrested him Sept. 24 on a beach near Galveston, Texas. By then, police had charged Matthew with abduction with intent to defile, or sexually molest, the 18-year-old Graham.

That arrest on a violent felony charge gave police authority under state law to take a cheek swab without Matthew’s consent after he was returned late Friday to Virginia, where he is being held without bond in the Albemarle-Charlottesville Regional Jail. On Monday, Virginia State Police announced that his arrest had produced a “significant breakthrough” that investigators of Harrington’s death will pursue.

Matthew is scheduled to appear by video link for a bond hearing in Charlottesville General District Court on Thursday. He has not been charged with either Harrington’s slaying or the Fairfax City rape.

Harrington, a Virginia Tech student from Roanoke, left UVa’s the concert and was denied re-entry, stranding her outside. Matthew, a hospital worker, had a license to drive a taxi at the time, according to the state Department of Motor Vehicles.

Her parents have always believed she was the victim of a serial offender. They even started “Help Save the Next Girl,” a non-profit foundation aimed at protecting young women. Discussing the case Tuesday outside their home north of Roanoke, Dan Harrington said Matthew’s arrest triggered a mixture of relief, sadness and anxiety over revisiting details of their daughter’s death.

But the top priority, he said, should be finding Hannah.

“I think it’s the most important thing,” he said. “I mean, Morgan’s in a box in the living room. We know where she is; she’s not coming back. Hannah, there’s still hope for Hannah. And I think that it’s critical for us to for the community to find her.”

While Virginia State Police have released no details about their forensic evidence, the FBI said in 2012 that DNA links the Harrington case with a rape in the city of Fairfax on Sept. 24, 2005. A 26-year-old woman was abducted and sexually assaulted while walking home from the store at about 10 p.m. on a Saturday night, police said; the assailant grabbed her from behind, dragged her into a wooded area behind some townhomes, and fled when he was startled by a passerby, police said.

At the time, police described the assailant as a black man in his mid-20s to mid-30s with a medium to heavy build, short hair and a beard. Matthew’s current description: black, 6-feet-2, about 270 pounds with dreadlocks.

Matthew’s lawyer, James Camblos, said he met with his client for about 2 1/2 hours Tuesday but still doesn’t know what evidence police have.

Graham’s disappearance is on the minds of many people in Charlottesville. Having lunch on a park bench near the courthouse, Cora Kessler, 21, said she has lived in the area whole life and this case has made her more cautious, but she still believes her community is safe. “I don’t want people to get the idea that it’s full of serial killers,” she said.

Neighbors of Matthew said they are shocked, frightened and disturbed by the accusations against him.

“It’s scary for any woman to be out there,” said Bev Johnston, whose apartment is in the same building as Matthew’s.

–Alan Suderman and Larry O’Dell / Associated Press. O’Dell reported from Richmond, Virginia. AP Writers Jonathan Drew contributed from Roanoke, Virginia, and Matthew Barakat from McLean, Virginia.