TACOMA — It’s no stretch to say the first three months of 2018 have been unusually deadly in Pierce County and Tacoma. Homicides surged in the first quarter. As of March 22, the number stood at 23. That tally nearly triples the nine homicides recorded through the first 81 days days of 2017 and sets a pace that could lead to the most violent year in two decades. The incidents run a sad gamut, from a lethal road-rage confrontation on the shoulder of Interstate 5, to the slaying of a mother and father in Buckley, and the fatal shooting of county sheriff’s deputy Daniel McCartney, who was responding to a reported robbery in Frederickson.