Zhao is an Australian citizen, who committed a crime, albeit a horrifically brutal one, in Australia before fleeing to China.
In the absence of an extradition treaty, he was tried and ultimately convicted in China, a country with little regard for legal niceties or judicial process. While Australian authorities were assured the death penalty would not be imposed, it's not clear what, if any, other safeguards were sought or received.
"There are some basic conditions on criminal prosecutions that should have been sought and apparently were not .... things like an open court trial, access to counsel and the right to challenge evidence," says Stephen Blanks, President of the NSW Council for Civil Liberties.