CHICAGO – Cook County Crime Stoppers is offering a $10,000 reward for information that helps Chicago cops solve a horrific murder. First responders found 29-year-old Al Walker on fire in an alley behind the 6700 block of South Prairie a little after 5 p.m. on October 12. He died three days later. According to the Cook County Medical Examiner’s Office, Walker was physically assaulted and then set on fire inside a motor vehicle. Officials declared his death a homicide.