Milan, November 30 - A Milan court on Wednesday closed a trial against a 64-year-old baker for the murder of prosecutor Bruno Caccia in Turin in 1983 due to a procedural problem. However, the suspect, Rocco Schirripa, has not been able to leave jail as prosecutors have already reopened the investigation. Schirripa was arrested in December 2015 after investigators sent an anonymous letter to Domenico Belfiore, a former kingpin of Calabria's 'Ndrangheta mafia in Piedmont who is serving a life sentence for the assassination. The letter contained the photocopy of a newspaper article reporting the mobster's 1983 arrest with the name Rocco Schirripa - who was in the service of the Belfiore family at the time of the assassination - written on the back. Investigators then probed his reaction using wire-taps. Caccia was shot dead on the evening of June 26, 1983 while he was out walking his dog near his home in Turin. Investigators claim he was first shot and wounded by Belfiore from a car before being finished off by Schirripa with a bullet to the head.