DETROIT – After more than 30 years, a family is hoping the public can help police solve a cold case. Rudolph “Rudy” Mark III was 16 years old when he was killed on May 6, 1987. The incident happened on Northlawn Street near 8 Mile Road and Wyoming Avenue on Detroit’s west side. “My son was five of eight children, killed, murdered for no reason,” said Rudy’s mother Paulette Benton. Maybe somebody may know who killed him.”Crime Stoppers is offering a cash reward of up to $2,500 for information leading to an arrest.