The fatal shooting of a Black man by police in Philadelphia Monday afternoon triggered large protests overnight.As John Yang reports, it is the latest police killing in this country in recent months to provoke strong public outrage.Violent protests broke out overnight in Philadelphia, with more than 30 officers injured.Oh, he hit a cop. Oh, my God, he hit a cop. He hit a cop.More than a dozen people arrested, cars set aflame...I was on my way home. This is in the middle 52nd Street.And stores looted. Philadelphia City Councilman Isaiah Thomas:Like so many Philadelphians, it was hard to wake up this morning after seeing so many graphic images of what took place in our city last night.We see these incidents. We recognize our city has a lot of problems.The spark? A killing Monday of a 27-year-old Black man named Walter Wallace Jr. captured on video.Just before 4:00 p.m., two officers responded to a report of a man with a knife in a predominantly Black neighborhood in West Philadelphia.Wallace approached the officers, they opened fire. Oh! Oh! Oh. Oh, my God.He was rushed to Penn Presbyterian Medical Center, where he died.Philadelphia Police Sergeant Eric Gripp described what happened.