Zou's barrister asks judge to consider his agepublished at 12:49 British Summer Time
Daniel Sandford and Claire Ellison
Reporting from Inner London Crown Court
Zou's barrister Mark Cotter KC says "the road to rehabilitation may be a long one", but adds there are "aspects" of the pre-sentence report that show "he is reflecting on what has taken place".
He also asks the court to consider Zou's age, saying that with a younger person, there is a greater chance of change.
There is evidence Zou, 28, will not be dangerous indefinitely, the defence says.