Need a Motive for this Murder.?

Investigate the murder of Brian Hegarty, a wealthy commodities supplier. His body was discovered last week in a local park. The contents of Mr.Hegartys wallet appeared to be intact and only a smal sample of gold was found on the scene. His account showed that he recently sold 170kg of gold to a struggling local computer comany WhizzDisks. The accounts show that WhizzDisks managment had cause only to be grateful to Mr.Hegarty. He had completed their order on time and in budget and had even managed to supply the gold at 10% below the current market value of the metal. Your team's task is to design and perform an experiment to test possible motives for Mr.Hegarty's murder.