COLUMBIA, S.C. — A 70-year-old man who was shot and wounded by a deputy as he reached for his cane during a traffic stop was the ninth person shot by a law officer in South Carolina so far this year, state officials say, bringing the pace of police-involved shootings to more than one a week. That would mark the highest rate of such shootings in South Carolina since state officials started keeping statistics in 1999. Whether the figure is bucking or following national trends is not clear however, because the FBI and other federal agencies don’t keep statistics on the number of police shootings across the U.S. That prevents researchers like University of South Carolina criminology professor Geoffrey Alpert from being able to figure out if police officers are shooting more because they face more danger, or they are more likely to fire their weapons before the threat to them is fully known.