WASHINGTON — Local and federal authorities on Thursday will solicit the public's help in catching a man who they say is linked by DNA and other clues to a series of sexual assaults in Montgomery County and to the killing of a young scientist in Georgetown in the 1990s.

The announcement of a publicity campaign by law enforcement officials Thursday is modeled after a similar effort that helped lead to the arrest earlier this year of Aaron Thomas, who authorities believe is responsible for a string of sexual assaults up and down the East Coast.

In the case of the alleged serial rapist, authorities plan to unveil a website about the case at a news conference Thursday at the U.S. Attorney's office for the District of Columbia.

Officials say the man is believed responsible for nine attacks on women between 1991 and 1998 — including the August 1, 1998 killing of Christine Mirzayan, a 28-year-old biochemist who was accosted by a man while walking home to a Georgetown University dormitory in Northwest Washington, then sexually assaulted and bludgeoned with a heavy object.

The remaining sexual assaults or attempts occurred in neighboring Montgomery County and generally took place between 6 p.m. and 9 p.m., targeting women from their teens to their mid- to late 40s and of varying ethnic backgrounds.

Seven of the nine attacks are linked by DNA and the remaining two are connected by similarities in how they were carried out, according to a law enforcement official who spoke on the condition of anonymity because the details of publicity campaign had not yet been announced.

The outreach effort is being announced by U.S. Attorney Ron Machen, D.C. Police Chief Cathy Lanier, Montgomery County Assistant Police Chief Russell Hamill, and Ron Hosko, the special agent in charge of the criminal division of the FBI's Washington field office.

Police had previously said that they weren't sure if the suspect was still in the region, in prison or even still alive.