STOCKTON, Calif. — A man suspected in Northern California serial killings has been charged in four additional slayings this week, bringing the total to seven deaths since April 2021, authorities said.The shootings terrorized the Central Valley city of Stockton earlier this year as police searched for a man clad in black who appeared to be “on a mission” as he hunted victims for ambush-style shootings.Three of the four slayings listed in court documents Tuesday have already been disclosed by authorities — who earlier said they had linked suspect Wesley Brownlee to the killings of six men and the wounding of a woman — but charges had not been filed.Brownlee was initially only charged in the deaths of three victims in Stockton: Jonathan Rodriguez Hernandez, 21, who died Aug. 30; Juan Cruz, 52, who died Sept. 21; and Lawrence Lopez Sr., 54, who died Sept. 27.The amended complaint, filed Tuesday, additionally charges Brownlee with the killings of Paul Yaw, 35, who died July 8, and Salvador Debudey Jr., 43, who died Aug. 11, in Stockton, as well as the Alameda County fatal shootings of Juan Vasquez Serrano, 39, on April 10, 2021, and Mervin Harmon on April 16, 2021."