Kieran Denman, Catherine Lambert and Imam Sis were charged with aggravated trespass following a demonstration at the Defence Procurement, Research, Technology and Exportability (DPRTE) exhibition held at the Motorpoint Arena in Cardiff on 27 March.
The defendants were protesting the arms fair mainly on the basis that the weapons have found their way to Afrin in Syria, and assisted in the onslaught of violence in that area leading to the destruction of many Kurdish homes and communities.
The demonstrators were accused of trespassing on private land near a security gate at the back of the arena and failing to move after warnings from police officers. They denied these allegations.
The campaigners were due to stand trial at Cardiff Magistrates's Court on Tuesday 3 July, but the charges were dropped before the trial began after it emerged the prosecution had failed to disclose vital evidence to the defence. A successful argument was made by the counsel of the defendants to exclude evidence on the basis that the prosecution failed to serve the vital evidence until shortly before the trial, which significantly prejudiced the defendants.
Audrey Cherryl Mogan of Garden Court Chambers said that the defence were only provided with the evidence three working days before the trial was due to start. District Judge Bodfan Jenkins said:
"In the circumstances I am satisfied that the defence would be unable to cross examine effectively, and that the defendants wouldn't have the opportunity to show that they had not trespassed on land at the relevant time... I make the judgment that [the evidence] should be excluded."
Audrey Cherryl Mogan and Meredoc McMinn represented Imam Sis and Catherine Lambert respectively, instructed by Kellys Solicitors. Camila Zapata Besso represented Kieran Denman, and was instructed by Hodge Jones & Allen.
The case was reported in Wales Online.