not hurt. the suspect in custody is 25-year-old vincent pinkney. police sources say he's a known gang member with 16 prior arrests who was out on parole. that deadly attack is one of the latest examples in a growing wave of homicides in cities across the country. law enforcement experts blame a combination of more guns and fewer cops. here's cbs' jeff pegues. >> reporter: it's been a violent year in chicago's kenosha county. over 1,000 people have been murdered. in philadelphia, over 500. senseless violence, which often claims the lives of innocent children like eight-year-old p.j. evans. >> hi! >> reporter: in prince george's county, maryland. killed in a barrage of gunfire during a family gathering. antoine dotson is p.j.'s uncle. >> an eight-year-old who is a promising student, who had so many great things going for him to lose his life. >> reporter: michael harrison is baltimore's police commissioner, where murders are