E81: “The Yorkshire Ripper” Pt. 2 - Peter Sutcliffe

From the years 1969 to 1981, a serial killer known as the Yorkshire Ripper freely roamed the streets of Yorkshire, England. Police were so determined to find him, they interviewed over 250,000 people. Sutcliffe had been brought in for questioning on nine separate occasions and each time he walked out a free man. How would they eventually catch him?