Theories include the possibility that violence is driven by the prevalence of guns in America, or by less aggressive police tactics or a decline in prosecutions for misdemeanor weapon offenses, Nagin said CHICAGO: Mass shootings and violence killed and wounded people across the United States this weekend, including at least 60 shot in the Chicago area alone. Four people were found shot to death in a small Idaho town, a Pennsylvania state trooper was killed in an ambush, and bullets struck 11 teenagers, killing one, at a party in Missouri. The shootings happened in cities and rural areas alike, following a surge in homicides and other violence over the past several years that accelerated during the coronavirus pandemic. Officers responded to mass shootings in Washington state, Philadelphia, San Francisco, Southern California and Baltimore. “There’s no question there’s been a spike in violence,” said Daniel Nagin, a professor of public policy and statistics at Carnegie Mellon University. “Some of these cases seem to be just disputes, often among adolescents, and those disputes are played out with firearms, not with fists.” Researchers disagree over the cause. Theories include the possibility that violence is driven by the prevalence of guns in America, or by less aggressive police tactics or a decline in prosecutions for misdemeanor weapon offenses, Nagin said. Only the Idaho killings fit the definition of a mass killing in which four or more people die, not including the shooter. However, the number of injured in most of the weekend cases matches the widely accepted definition for mass shootings. Here’s a look at some of the shootings this weekend: CHICAGO Five people were shot, two fatally on the city’s South Side on Sunday evening when someone opened fire from a car that pulled up to a gathering, according to police. Another four men were shot, one fatally, during an altercation in a garage in the West Side neighborhood of Austin around 3 a.m. Sunday, police said. Five others including a teenage girl were shot early Saturday near Lincoln Park Zoo, and two dozen more were shot in other incidents since Friday evening, city data shows. Meanwhile in the suburbs, at least 23 people were shot, one fatally, early Sunday in a parking lot where hundreds of people had gathered to celebrate Juneteenth, authorities said. The White House issued a statement calling the violence a tragedy and saying the president was thinking of those killed and injured. Illinois Gov. JB Pritzker said in a statement that he was monitoring the investigation. KELLOGG, IDAHO Police in Idaho arrested a suspect in a shooting that killed four people on Sunday at an apartment complex behind a church. Responding officers found four people, all dead from gunshot wounds, at a residence in Kellogg that’s behind the Mountain View Congregational Church, according to the Shoshone County Sheriff’s Office and news reports. Idaho State Police said a 31-year-old man was detained, KXLY-TV reported. ST. LOUIS An early Sunday shooting in a downtown St. Louis office building killed a 17-year-old and wounded 11 other teenagers, the city’s police commissioner said. St. Louis Metropolitan Police Commissioner Robert Tracy identified the victim who was killed as 17-year-old Makao Moore. A spokesman said a minor who had a handgun was in police custody as a person of interest. Teenagers were having a party in an office space when the shooting broke out around 1 a.m. Sunday. The victims ranged from 15 to 19 years old. A 17-year-old girl was trampled as she fled, seriously injuring her spine, Tracy said. WASHINGTON STATE Two people were killed and two others were injured when a shooter began firing “randomly” into a crowd at a Washington state campground where many people were staying to attend a nearby music festival on Saturday night, police said. The suspect was shot in a confrontation with law enforcement officers and taken into custody, several hundred yards from the Beyond Wonderland electronic dance music festival. CENTRAL PENNSYLVANIA One state trooper was killed and a second critically wounded just hours apart in central Pennsylvania on Saturday after a gunman attacked a state police barracks. The suspect drove his truck into the parking lot of the Lewistown barracks about 11 a.m. Saturday and opened fire with a large-caliber rifle on marked patrol cars before fleeing, authorities said Sunday. Lt. James Wagner, 45, was critically wounded when he was shot after encountering the suspect several miles away in Mifflintown. Later, Trooper Jacques Rougeau Jr., 29, was ambushed and killed by a gunshot through the windshield of his patrol car as he drove down a road in nearby Walker Township, authorities said. The suspect was shot and killed after a fierce gunbattle, said Lt. Col. George Bivens. “What I witnessed ... was one of the most intense, unbelievable gunfights I have ever witnessed,” Bivens said, lauding troopers for launching an aggressive search despite facing a weapon that “would defeat any of the body armor that they had available to them.” A motive was not immediately known. SOUTHERN CALIFORNIA A shooting at a pool party at a Southern California home left eight people wounded, authorities said Saturday. Authorities were dispatched shortly after midnight in Carson, California, south of Los Angeles, KABC-TV reported. The victims range in age from 16 to 24, the Los Angeles County Sheriff’s Department said. BALTIMORE Six people were injured in a Friday night shooting in Baltimore. All were expected to survive. Officers heard gunshots in the north of the city just before 9 p.m. and found three men with numerous gunshot wounds. Medics took them to area hospitals for treatment. Police later learned of three additional victims who walked into area hospitals with non-life-threatening gunshot wounds. The wounded ranged in age from 17 to 26. SAN FRANCISCO Six people were injured after a “car-to-car” shooting in the streets of San Francisco on Sunday evening, police said. Two victims sustained gunshot wounds, one with life-threatening injuries, in the moving shootout beginning shortly before 7 p.m., San Francisco Police Chief Bill Scott said at a news conference Sunday. Suspects in two cars, a black SUV and a white sedan, “drove very recklessly and chased each other while engaged in gunfire” near the northern waterfront, Scott said. The area includes Fisherman’s Wharf, one of the city’s busiest tourist areas. Three victims were injured by glass shards caused by “errant gunfire,” Scott said, with none of the injuries considered to be life-threatening. Two girls, ages 10 and 16, were struck by one of the two vehicles while walking their bicycles across the street. The younger girl was injured and transported to a hospital with non-life-threatening injuries while the older girl was not injured. PHILADELPHIA A 4-year-old boy was among five victims of a shooting in south Philadelphia Saturday night. Police responded to the block shortly before 8 p.m. Saturday and found a 58-year-old woman with gunshot wounds to the legs, a 54-year-old woman with gunshot wounds to her wrist and leg, and the boy, who was brought to Presbyterian Hospital with a gunshot wound to the abdomen. A 30-year-old man also arrived at the hospital with a gunshot wound to the wrist and a 40-year-old man was brought in with a gunshot wound to the abdomen. The last victim was listed in critical condition; all others were said to be in stable condition.