FBI(WASHINGTON) — Federal prosecutors in Washington D.C. announced the first ever “John Doe” indictment of a still unknown suspect’s DNA on Tuesday, as part of an ongoing investigation into a string of violent sexual assaults of women in hotel rooms in the D.C. area between 1998 and 2006.The long-unsolved serial rapist case has vexed area law enforcement for years. The suspect, who became known as the “D.C.-area hotel rapist” terrorized mostly hotel maids by sneaking into rooms they were cleaning and sexually assaulting them.“This individual preyed on members of the D.C. region for nearly a decade,” Washington Metropolitan Police Department Chief of Police Peter Newsham said in a statement. “We have not deviated from our goal of holding this person accountable for his heinous actions and feel confident that our recent progress will lead to his identification.”Six of nine attacks on women in hotel rooms have been definitively linked to the suspect through DNA, and suspicious activity reported in five other area hotels may be related, authorities said. The attacks unfolded in hotels in Maryland, Virginia and Washington D.C.In several of the incidents, the assailant used a box cutter, a necktie or a rope to threaten or assault his victims.U.S. Attorney for the District of Columbia Jessie K. Liu said in the statement that “despite the passage of time, we have never forgotten these victims.”“Working with the public and our law enforcement partners,” he said in the statement, “we are hopeful that we finally will be able to hold this serial rapist accountable for his brazen crimes,” said Jessie K. Liu, U.S. Attorney for the District of Columbia.Authorities also released a relatively new type of suspect sketch – not a composite created based on eyewitness descriptions, but one created in a lab using the suspect’s DNA to produce a composite sketch of the possible suspect which includes eye color, skin color, hair color and a face based on biogeographic ancestry with age-progression.Special Agent in Charge of the Federal Bureau of Investigation’s (FBI’s) Washington Field Office Matthew Desarno urged the public to take a close look at the suspect sketch.“The reason we are here today, is about bringing closure for the victims,” Desarno said at a press conference. “There are now multiple women that have been attacked, assaulted and raped,” said in the statement.“We stand here on behalf of them in the hope that a recollection, a memory jogged, a subsequent text or phone call with that information with result in the closure that these victims deserve.”Copyright © 2018, ABC Radio. All rights reserved.