State police responded to about 100 fewer crashes and only half the number of fatal crashes during this year’s Christmas holiday and weekend compared to last year. State police said they investigated 632 crashes leading to 153 injuries and four deaths  statewide over the four-day holiday weekend.  54 of the crashes during this year’s holiday, which state police counted from Dec. 24 to Dec. 27, involved alcohol, including one fatality. Three of the people killed during that time frame were not wearing seat belts.