The 19-year-old black man who was shot and killed by an officer on Friday was unarmed, the police chief of Madison, Wisconsin, said on Saturday. The teen was identified as Tony Terrell Robinson Jr., a graduate of Sun Prairie High School, a family spokesman and authorities said. "It's a challenging time for this family right now. To lose a son, especially the way they lost a son," said the family spokesman, Michael Johnson. Chief Mike Koval said during a press conference the officer who shot Tony Terrell Robinson, Jr. identified the officer who shot Tony Terrell Robinson, Jr. as Matt Kenny, 45, and said he has more than 12 years of experience. Kenny was involved in a shooting in 2007 but was cleared of any wrongdoing because it was a "suicide by cop-type" case, Koval said. Police said Kenny shot Robinson on Friday night after Robinson assaulted the officer. Kenny is on administrative leave pending the results of the investigation. Some 100 protesters took to the streets of Madison after the shooting, according to witnesses and reports, with video showing the crowd chanting: "Who can you trust? Not the police."