SALT LAKE CITY — When a man was shot and killed in Liberty Park on Sunday, he was identified publicly only as homeless. They knew him as Marquise, or by the name he used around Liberty Park: Kratos. According to a probable cause affidavit, Salt Lake City police were called to Liberty Park at approximately 3:33 p.m. Sunday. While the police documents describe the final confrontation, Kratos’ friends said it was only one part of his story. Youngren remembered him as a talented rapper who could improvise long verses and dreamed of making music.