On 1 May, the longest-running murder trial in the state's history came to an end when Tipperary farmer Patrick Quirke was found guilty of the murder of Bobby Ryan.A jury of 12 people found Quirke guilty of the murder of Ryan – known by locals in Tipperary as DJ ‘Mr Moonlight’ - by a majority verdict of 10 to 2. Quirke had pleaded not guilty but was sentenced to life in prison after the 13-week trial. Details of the DJ’s life, circumstances surrounding his death, as well as an affair involving the two men and Mary Lowry, were laid out in the court room.In this week's episode of The Explainer, we look at Patrick Quirke's conviction: what evidence did the jury hear? What do we mean by 'circumstantial evidence' and how big a role did that play in the case? How usual is it to have a majority verdict in a murder trial?To help us answer those questions, host Sinéad O'Carroll speaks to our reporter Gráinne Ní Aodha and barrister-at-law Marc Murphy.