In Argentina, tens of thousands of people marched Wednesday for the safe return of a witness whose recent testimony led to the conviction of a former chief of police. The witness, Jorge Julio Lopez, is seventy-seven years old. He went missing just one day after police commissioner Miguel Etchecolatz was sentenced to life in prison for murder, torture and kidnapping during Argentina’s seven year dictatorship ending in 1983. The comissioner’s conviction was one of the first since Argentina’s Supreme Court overturned amnesty laws shielding Dirty War-era military and police officers from prosecution.