In 2003, he pleaded guilty to the statutory rape of four teenagers, including the two victims suing him.
Rockwell, which ran the plant for 15 years, pleaded guilty in March to 10 violations of environmental laws, including five felonies.
In January 1980, he pleaded guilty to several felonies, including embezzlement and fraud.
In all he pleaded guilty to six charges, including two counts of conspiracy to commit insurance fraud.
On March 1, 1994, he pleaded guilty at a secret court hearing to the charges against him, including complicity in 36 murders.
He also pleaded guilty to a range of other charges, including assault and abandonment of a dead body.
The men were sentenced for crimes they pleaded guilty to, including racketeering, assault and participation in the killing, as part of their cooperation agreements.
Nicholson pleaded with the authorities to evacuate them, including Natasha, a nine-year-old who had been abandoned by her mother.
In February, the first of five people arrested in that case pleaded guilty to six counts, including felony murder.
In 1996, 42 department elevator inspectors were suspended and 18 eventually pleaded guilty to federal charges, including extortion.