jamie pettingill , who threatened to slice off a schoolboy 's face , was ordered to complete 350 hours of community service after being found guilty of stealing six mobile phones .
pettingill robbed two women , a man and two other men , were charged with the murder of victoria police constables steven tynan , 22 , and damian eyre , 20 .
the officers were brutally killed when responding to a report of an abandoned car around 5 am on october 12 , 1988 .