A former Uber driver accused of sexually assaulting a female passenger last year is now facing charges in five unsolved Boston rape cases going back almost a decade, the district attorney and police officials announced Tuesday.

Suffolk District Attorney Daniel Conley said Alejandro Done, 46, who has been in custody since December, has been linked by a DNA sample he was required to give in that case in Cambridge to several sexual assaults in Boston between 2006 and 2010.

Conley said at a news conference the apparently random attacks on women walking alone late at night, mostly on summer weekends, were "violent, predatory." He said the victims in all the cases gave a consistent description that resembles Done, who had no previous criminal record.

"The real break in the case happened when state police criminalists, on their own, said, 'Let's run his profile through the database.' And sure enough, they got a hit," Conley said.

He said the state police crime lab discovered the DNA link Monday night.

"These cases have been worked tirelessly for the last nine years," said State Police Superintendent Col. Richard McKeon. "We never forgot."

Conley's spokesman said Done has been charged with rape in attacks in July 2006 in South Boston and July 2007 on the Esplanade along the Charles River. Charges are being prepared in three other sexual assaults, in June 2007 and July 2009 along the Esplanade and in June 2010 in South Boston, he said. An arraignment has not been scheduled.

Done has pleaded not guilty in Middlesex County to kidnapping and raping a woman he picked up after she summoned an Uber driver to take her home to Cambridge from Boston. Prosecutors said he drove to a location she wasn't familiar with, pulled over in a secluded area and sexually assaulted her in the back seat after a struggle. Cambridge police identified him as a suspect through Uber records. He is held pending trial.

A message seeking comment was left for Done's attorney in that case. It's not determined who will represent him in the new cases.

Uber said Tuesday that Done was not a driver for the ride-hailing service when the Boston attacks took place, and had passed a criminal background check when he was hired.

"We are grateful that we were able to work closely with law enforcement to assist in their December 2014 investigation that has led to these additional charges," the company said.