A 71-year-old man is standing trial over a spate of Sydney bombings and shootings that terrorized Australia's legal fraternity more than 30 years ago.

Leonard John Warwick has pleaded not guilty in the New South Wales state Supreme Court to four murder charges and another 20 charges relating to crimes between 1980 and 1985. The crime spree became known as the Family Court bombings because it targeted Family Court judges and their families.

Opening the trial on Tuesday, prosecutor Ken McKay told the judge that Warwick had been involved in a long-running Family Court dispute with his former wife Andrea Blanchard over their infant daughter that "inextricably linked" him to the crimes. He faces a potential life sentence.

The trial will continue on Wednesday before a judge with no jury.