As BBC News reported in 2004, Yang's three-year killing spree ranged across the provinces of Henan, Anhui, Shandong and Hebei. He used a hammer to kill, and sometimes murdered entire families.
In an interview shown on Chinese television after his trial, Yang said that he was a misfit who simply enjoyed committing murders.
"When I killed people I had a desire (to kill more). This inspired me to kill more. I don't care whether they deserve to live or not. It is none of my concern," Yang said.
"I have no desire to be part of society. Society is not my concern," he said.
Chinese police finally got lucky, catching Yang when they detained him during a routine inspection of entertainment venues. After he confessed to the crimes, his trial only lasted an hour before he was found guilty in 2004.
A few weeks after the verdict, Chinese state media announced that Yang had been executed, though it didn't detail the method used [source: BBC News].