“We wanted to be quick and timely to share that information with the Graham family,” he said.

Ms. Graham, who grew up in Fairfax County, outside Washington, was last seen in the early morning hours of Sept. 13, spotted outside a downtown pub on security camera footage.

Image Hannah Graham Credit... Reuters

Less than two weeks later, Jesse Leroy Matthew Jr., 32, a hospital worker, was arrested in Galveston, Tex., and returned to Virginia, accused of being involved in her disappearance. The police said Mr. Matthew, who has been charged with abduction with intent to defile, was the last person to be seen with Ms. Graham.

The police have also connected Mr. Matthew to the disappearance of another woman, Morgan D. Harrington, in 2009.

The Virginia State Police said that investigators had found a “new forensic link” in the death of Ms. Harrington, 20, a Virginia Tech student who disappeared from the University of Virginia campus during a concert. Her remains were found months later, in January 2010, on a farm in southern Albemarle County.

The discovery of remains on Saturday was a “significant development,” said Col. Steve Sellers, the chief of the Albemarle County police, who noted that the case had shifted into a death investigation.