Police are trying to find a man who sexually assaulted two teenage trick-or-treaters in Virginia on Halloween after linking him to more than a dozen attacks on women since 1997.

Police said Wednesday that DNA evidence links the attacker in the Virginia case to 13 crime scenes in that state, Maryland, Connecticut and Rhode Island.

Authorities believe the unique timeline could provide clues in identifying a suspect. Most of the rapes occurred between 1997 and 2001 in the D.C. suburbs. After a five-year hiatus, the man was linked by DNA to a peeping-tom incident in 2006 in Rhode Island and a 2007 rape in Connecticut.

The most recent attack occurred on Halloween in Prince William County.