There's nothing like locking the prison door after the dangerous criminal has done his worst. It is tantalizing to think that if John F. Thanos had been held in prison the 18 months remaining on his sentence, three people might still be alive. But he would have gotten out eventually, and his history shows he was a dangerous man.
State officials at first denied they had used "good time" from a sentence imposed after a 1969 rape to help justify Thanos' early release, but now say they did. Attorney General J. Joseph Curran Jr. noted that Thanos was released from that sentence in 1986. The so-called crossover rule on concurrent sentences should not have applied. Public Safety Commissioner Bishop L. Robinson told a legislative hearing Mr. Curran was right, but it is very late to be tightening up the rules.
A man with a record like Thanos should never have been released early, and corrections officials should have realized it. Thanos spent just 26 days free after his 1986 release, then committed robbery. Prisons have mental-health specialists to examine a prisoner's background and attitudes to determine how well he is prepared for life among peaceful neighbors. It is difficult to believe they could misread a man as violent as Thanos.