STOCKTON — An unidentified man died Thursday night when he crashed his motorcycle while speeding down a residential street in north Stockton, according to police and witness statements.The crash occurred about 8:15 p.m. on Knickerbocker Drive west of Montauban Avenue. A man who witnessed the crash said the motorcyclist was going east on Knickerbocker Drive and traveling about 60 mph when he lost control of his motorcycle.“He was flying down the street and his [...]