A judge has ruled that gardaí used a threat to induce a man to confess to being the owner of a firearm found in a box of toys in his bedroom.

Philip Finnegan (26) had pleaded not guilty at Dublin Circuit Criminal Court to unlawful possession of a blank firing semi-automatic pistol at his home in Mary Aikenhead House, James Street, Dublin on March 14, 2013.

During a search of his home gardaí located the gun in a box, which also contained toys and video games, located in a bedroom Mr Finnegan shared with his three younger brothers.

In garda interviews Finnegan said the firearm belonged to his brothers but later told officers to charge him and not his brothers.

After viewing video footage of Mr Finnegan’s interviews in custody Judge Mary Ellen Ring ruled that garda references to arresting his brothers were threats that undermined the voluntary nature of his statement.

On foot of this ruling the Director of Public Prosecutions entered a nolle prosequi in the case, effectively dropping the charges. The ruling came after an application by Seamus Clarke BL, defending, at the start of the trial.

Mr Finnegan initially told gardaí the firearm belonged to his brothers. Gardaí then asked him if he wanted them to have to arrest his brothers if the firearm was found to be a real gun.

They later asked him: “Would you not save your brothers the trouble of claiming ownership for it? You would still let your brothers be in trouble for it.”

He told them: “I wouldn’t let my brothers get charged on a firearm, but it is theirs.” Gardaí repeatedly told him they would have to arrest his brothers and suggested he had his only chance now to “protect them”.

He later told gardaí, who were transcribing the interview: “Just write that it’s mine, if charges are to be brought, I’ll be charged.”

Judge Ring said that encouraging a suspect in a particular direction during a garda interview can affect the voluntariness of their statement. She said she was satisfied that the references to Mr Finnegan’s brothers were capable of being taken as a threat of trouble for them in the future.

She said the onus is on the prosecution to prove a statement is voluntarily made and that this onus of proof was not met in this case.