China's former 148th richest person was just executed for running a massive crime ring

When Liu and 35 other suspects were charged last year, the state news agency Xinhua said it was "the largest prosecution of a criminal gang by mainland authorities in recent memory."

Liu was ranked 148th on Forbes' list of China's richest people in 2012. According to South China Morning Post, his gang activity pulled in almost $7 billion and he was worth $855 million.

The execution inspires nervousness in other high-ranking officials in China, especially as President Xi Jinping moves forward with his anti-corruption campaign, as well as his promise to take out even prominent corrupt party members.

CNN reported that many senior party officials were watching Liu's trial closely in May, looking for any indication that Zhou Yongkang, a former security czar linked to Liu, might be next. Liu was said to be close with Zhou and have done business with his son.

In December, Zhou was arrested. He will go to trial for bribery, adultery, and revealing state secrets.

Liu started his company Hanlong Group in 1997 and built it into a gang-run empire. According to Xinhua, Liu and his associates made money off everything from property and mining to loansharking and stock manipulation. To intimidate others and protect his business, Liu promoted gangsters who were most willing to kill.

Police found three grenades, 20 guns, 677 bullets, 2,163 shotgun cartridges and more than 100 knives after the gang bust, Xinhua reported. At his trial, Liu faced 15 charges including murder, financial crimes, bribery, running casinos and selling firearms illegally.