Fairfax County police have turned to a cutting-edge technique utilizing DNA to create composite images of a man they believe carried out the killings of two Springfield women months apart in 2006.

The images released Wednesday use the man’s genetic material to construct facial images that approximate what he may have looked like at ages 25, 40 and 55. DNA collected from the scenes of the crimes linked the same unidentified man to the slayings of Marion Marshall and Marion Newman.

Besides having the same first names, the woman shared other similarities, police said. Both were in their 70s, neither had children, neither was married and both lived alone at the time of their deaths. They lived a couple of miles from each other.

Police said both women were sexually assaulted before they were strangled and suffered blunt force trauma. The suspect’s DNA was entered into a national database more than a decade ago but has produced no hits.

Marion Marshall was last seen alive on Aug. 14, 2006. Detectives believe she got groceries before heading to her home in the 6600 block of Bostwick Drive, where she was killed.

Marion Newman was last seen alive on Nov. 19, 2006, when she visited her mother in a senior living community in Springfield. She was supposed to return the next day, but a friend found her dead inside her home in the 7100 block of Reservoir Road on Nov. 21, 2006, police said.

Parabon NanoLabs, a Northern Virginia company, produced the composite images. Police do not know how old the man was at the time of the crimes.