Speaking at the Law School Saturday, Simon Wiesenthal, the famed Nazi hunter, said 150,000 Nazi war criminals are living freely around the world today. Many of them are residents of the U.S. and Canada, he said.

Wiesenthal, who has been chasing Nazi war criminals for the last 40 years and who helped bring Hitler's henchman Adolf Eichman to trial in Israel, said international politics often prevent investigators from securing the arrest of Nazi murderers.

"In my opinion, everyone who was involved in a holocaust--in genocide--has not the right to die in peace," Wiesenthal said, drawing applause from the mixed audience of 450.

Wiesenthal, who is 77 years old, said he continues his global pursuit partly to deny the perpetrators of the Holocaust peace of mind. "When two Nazis have a quarrel, one threatens the other: I will go to Wiesenthal and I will tell him about you," Wiesenthal said.

Wiesenthal said a variety of roadblocks stand between Nazi hunters and their quarry. The accused criminals, having reached their late eighties, arouse sympathy in judges who find it hard to arrest elderly people.

The only way the world can prevent another holocaust from happening is to overcome racial hatred once and for all, he said.