However, Eric Smith had been diagnosed by a defense psychiatrist with intermittent explosive disorder, a mental disorder causing individuals to act out violently and unpredictably.
People over the disorder's minimum age of 6 may be diagnosed with intermittent explosive disorder without outbursts of physical aggression.
As his prison term expired, he was found to have "antisocial personality disorder" and "intermittent explosive disorder" but not any sexual compulsion.
He has been diagnosed with depression, attention deficit disorder and intermittent explosive disorder.
Lee estimated that one of every 50 Hongkongers suffers from intermittent explosive disorder, turning one into a "ticking time bomb" of rage and violence.
According to an article published by the Associated Press in June 2006, the behaviors typically associated with road rage are the result of intermittent explosive disorder.
The cause of intermittent explosive disorder has not been described to date.
"Intermittent explosive disorder" may be a cause of violence.
Rule out intermittent explosive disorder and atypical paranoid disorder.