A riot squad officer who hit a G20 protester twice with a metal baton will be told today if he broke the law.
Metropolitan Police Sergeant Delroy Smellie, 47, faces losing his job if found guilty of assaulting Nicola Fisher.
The officer, a member of the controversial territorial support group, went on trial accused of assault by beating last week.
City of Westminster Magistrates’ Court heard he clashed with demonstrators outside the Bank of England on April 2 last year.
A judge heard Ms Fisher ran in front of him hurling abuse during a vigil to mark the death of Ian Tomlinson the previous evening.
Nicholas Paul, of the Crown Prosecution Service, said he was justified when he shouted at her, pushed her back and struck her with the back of his hand.
But he said the officer went too far when he struck Ms Fisher across the thigh with the extendable metal weapon, known as an asp.
The clash attracted attention worldwide when amateur video footage of it was posted on the YouTube website.
Ms Fisher, of Brighton, suffered two bruises to her leg and enlisted Max Clifford to sell her story to a national newspaper for around £26,000 (€29,000).
She failed to attend the trial claiming she was suffering depression and feared being in the public spotlight again.
In his defence, Smellie said he feared for his safety when he was left isolated behind a line of his colleagues who were facing the other way.
The highly-trained and experienced officer, who is suspended from duty, said his actions were reasonable and proportionate.
The court heard Smellie has served at some of the most volatile protests of recent years, including those marking a visit by US president George W Bush.
District Judge Daphne Wickham, who heard the four-day trial without a jury, reserved her verdict until 2pm today.