His name was ABDUL NUMAN HAIDER. Why is he referred to as Numan Haider?
Youth camp mate says teen terrorism suspect shot dead by police in Melbourne seemed to be looking for answers
Because that was the name he commonly went by - it's a peculiarity of the way names work in Arabic - Abdul virtually never stands alone, but is virtually always accompanied by another more personal name - in this case Numan.
Guess he found one.