A police officer who shot a 64-year-old race relations adviser in the face with a Taser after mistaking him for a man wanted on drugs charges will face a charge of gross misconduct, it has emerged.

Acting sergeant Claire Boddie told Judah Adunbi, a community elder in Bristol, that he looked “familiar” and, after he refused to give his name, a scuffle broke out and she discharged the stun gun, hitting him in the jaw.

Boddie was found not guilty of assault by one of the country’s most senior district judges on Friday after a one-day trial. The Avon and Somerset officer told the court she discharged her weapon believing Adunbi had taken up a “fighting stance” and said had not known whether he had a weapon.

In court, Adunbi, also known as Ras Judah, said he had refused to give his name – as is his right – because he had done nothing wrong. Of the moment the stun gun was discharged, he said: “All I heard was a noise then I felt like my head was frying.”

Outside court he said: “I hope the fact that this prosecution was brought will mean that other black people in Bristol will not be Tasered in the face when out walking their dog, and that the police will finally realise that not all black people look or act the same.”

Supporters of Adunbi expressed concern that Boddie, an experienced officer, had mistaken him for a wanted man.

Desmond Brown, a spokesperson for the Justice 4 Judah campaign, said both men had dreadlocks but were not hard to tell apart. “He [Judah] is a community asset, a respected elder. He should have been known by the police.”

Brown – who wore a T-short reading: “I am Judah” – did not question the verdict but said elements of the legal process had hit confidence in the community. There has been anger that the trial was held in Salisbury, 60 miles from Bristol. Judah’s supporters believe it should have taken place close to where the incident happened so that justice could be seen to be done.

“Some of the process has been alarming,” Brown said. “Perhaps justice isn’t for us, for our community, for people of colour.” He claimed black people in Bristol were more likely to be stopped by police and more likely to be shot with a stun gun.

Adunbi’s solicitor, Tony Murphy of Bhatt Murphy, said: “Ras Judah now awaits the gross misconduct hearing.”

It can now be reported that Boddie’s legal team tried to prevent Adunbi from giving evidence at her trial. At a preliminary hearing this week the lawyers argued that because the whole incident was recorded on Boddie’s bodycam, no other testimony or extra video footage was needed. The judge rejected the attempt, saying Adunbi’s evidence was potentially relevant.

Adunbi has sat on Bristol’s independent advisory group, which forges links between the police and the community, and has worked with the Crown Prosecution Service’s local community involvement panel.

The incident unfolded last year outside Judah’s house in Easton, Bristol. A video taken by a passerby was widely shared on social media and made headlines around the world.

Footage shown in court of the moment Adunbi was shot drew gasps from his supporters in the public gallery.

Boddie was heard telling Adunbi: “You look familiar.” Judah refused to say who he was, telling Boddie and a colleague: “I’m an African black individual living in my own city.” Adunbi fell to the ground after he was shot and told the officers: “I’m nearly 70 … here’s my fucking ID.”

Clearing the officer, the district judge Tan Ikram said: “The issue for me is whether the prosecution have persuaded me that she didn’t act in self-defence. The prosecution failed to persuade me and she is found not guilty of assault for that reason.”

Facebook Twitter Pinterest Claire Boddie. Photograph: Ben Birchall/PA

Catrin Evans, the Independent Office for Police Conduct (IOPC) director with responsibility for Avon and Somerset, said: “The IOPC carried out a thorough investigation into the use of Taser which led to the Crown Prosecution Service decision to prosecute [acting Sgt] Boddie. We have found that [she] also has a case to answer for gross misconduct.

“Our investigation considered the actions of two officers, including the circumstances leading up to Mr Adunbi’s arrest and the use of Taser. Both Boddie and a second officer involved had no case to answer for misconduct in respect of allegations that they discriminated against Mr Adunbi on the basis of his race.”