By Martin Weil
Washington Post Staff Writer
Tuesday, October 7, 2008

Montgomery County police revealed new evidence last night in the area's recent home invasions, disclosing that a backpack stolen five years ago in the District was left at one of the robbery scenes.

Police said they think the same person committed at least three of six similar crimes, including one last month in which a 63-year-old Bethesda woman was killed. Five invasions occurred in Montgomery and one in the District. Targets have ranged in age from 63 to 92.

Police said the blue or purple North Face Mojave backpack was found at the scene of a Feb. 27 invasion in the 11000 block of Picasso Lane in Potomac in which the victim was a 78-year-old woman.

Police said items in the backpack included two baseball-style caps, marbles and a slingshot made from rubber bands with a piece of denim to hold a projectile.

Police said DNA evidence linked the homicide to two other Montgomery invasions, but they declined to say which two.

They said similarities existed among all the incidents but that there were differences, including in modes of entry. Some doors were unlocked; some were pried open. In all but one incident, the robber, said to be white or Latino, was masked.