Wisconsin police arrested a 15-year-old boy they suspect to be the gunman who opened fire at the Mayfair mall in Wauwatosa on Friday, sending eight to the hospital. The shooting stemmed from an altercation at the mall, Wauwatosa Police Chief Barry Weber said. “We do know there was some sort of altercation, and that’s when the bullets started flying,” he said at a news conference Sunday. Police said several other arrests had been made in connection with the shooting, according to the Milwaukee Journal Sentinel.