Authorities across US grapple with rash of violence in final days of spring [Video]

Communities across the country are grappling with a rash of violence in the final days of spring that included at least four mass shootings in one weekend, and continued Monday with stabbings outside an Indiana strip mall.On Saturday, a lone gunman opened fire at a recreational splash pad in suburban Detroit, injuring nine people including an 8-year-old who was shot in the head. In Texas, fatal gunfire broke out at a Juneteenth celebration, with two people pronounced dead.Other shootings and stabbings, in locations from Massachusetts to Indiana, marred the days before spring turns to summer as sweltering heat takes hold in many regions.Related video above: Numerous vigils held in the Rochester Hills, Michigan, area after the recent shooting incidentChris Dennison, a sociology professor at the University of Buffalo who researches crime, said the arrival of seasonable weather presents more opportunities for crime and violence, amid heightened concerns about mental health …