Erica Goode in The New York Times:
He was described, in the immediate aftermath of the Germanwings crash, as a cheerful and careful pilot, a young man who had dreamed of flying since boyhood. But in the days since, it has seemed increasingly clear that Andreas Lubitz, 27, the plane’s co-pilot, was something far more sinister: the perpetrator of one of the worst mass murder-suicides in history.If what researchers have learned about such crimes is any indication, this notoriety may have been just what Mr. Lubitz wanted. The actions now attributed to Mr. Lubitz — taking 149 unsuspecting people with him to a horrifying death — seem in some ways unfathomable, and his full motives may never be fully understood. But studies over the last decades have begun to piece together characteristics that many who carry out such violence seem to share, among them a towering narcissism, a strong sense of grievance and a desire for infamy.
…Serious mental illness, studies of mass killers suggest, is a prime driver in a minority of cases — about 20 percent, according to estimates by several experts. Far more common are distortions of personality — excesses of rage, paranoia, grandiosity, thirst for vengeance or pathological narcissism and callousness. “The typical personality attribute in mass murderers is one of paranoid traits plus massive disgruntlement,” said Dr. Michael Stone, a forensic psychiatrist in New York who recently completed a study of 228 mass killers, many of whom also killed themselves. “They want to die, but to bring many others down with them, whether co-workers, bosses, family members or just plain folk who are in the vicinity.” Mr. Lubitz, Dr. Stone noted, now ranks among the deadliest of mass killers, in a league with Adilson Marcelino Alves, who in 1961 killed as many as 500 people in a circus fire in Brazil, or Timothy McVeigh, the Oklahoma City bomber, who killed 168 people and injured more than 680 others.