The trial of a man accused of murdering the two sons of a retired Bermuda police detective has begun in Barbados.Yuri Agard is accused of fatally stabbing Justin, 21, and William Greene, 25, outside a nightclub on the Caribbean island in the early hours of March 26, 2006.The brothers’ parents are retired narcotics officer Ronald Greene and former CedarBridge Academy teacher Margo Greene.Agard, aged 18 at the time of the double killing, was originally charged with manslaughter but the charges were upgraded to murder in 2007.Inspector David Welch, public relations officer for the Royal Barbados Police Force, told The Royal Gazette that Agard’s trial began last week in the Number 5 Supreme Court of Barbados and was continuing this week.Useful website: www.barbadospolice.gov.bb.