Police have charged a 19-year-old woman with negligent homicide in connection with a weekend crash that killed two cyclists from Massachusetts. Investigators said a car driven by Darriean Hess of Seabrook was speeding, crossed the center line, and struck a group of riders at 8:30 a.m. Saturday on a bridge during an annual long-distance ride. Hess was also charged with assault Tuesday. The crash killed Pamela Wells of South Hamilton and Elise Bouchard of Danvers. Two other riders were injured. Police said Hess was stopped on the same road eight hours before the crash and ticketed for driving without a license. Police allowed a friend to pick her up and drive her car away.