One of the nation’s highest-ranking Catholics has been found guilty of indecently and sexually assaulting young Aboriginal men while he worked across outback Australia.

The jury returned the verdict in the case of former Bishop of Broome Christopher Alan Saunders, 76, on Thursday afternoon, and ultimately found him guilty of 13 charges, including unlawful and indecent assault and sexual penetration without consent.

The verdict follows a marathon three-week trial in WA’s District Court for the former bishop, who was initially committed to trial on 26 charges, ranging from indecent assault to sexual penetration without consent, against three Aboriginal men dating back as far as 2008.

However, on Friday seven of those charges were dropped, with Judge Martin Flynn telling the jury there was not enough evidence for them to be able to come to a verdict of guilt beyond reasonable doubt.

The jury deliberated for about seven hours before handing down their verdict on the remaining 19 charges on Thursday afternoon.

He was found guilty of 12 counts of unlawful and indecent assault, and one count of sexual penetration without consent.

However, the jury found him not guilty of a further four counts of unlawful and indecent assault, and not guilty of two counts of indecently dealing with a child over 16 under his authority.

The charges were alleged to have been committed when Saunders was working across the Kimberley as the Bishop of Broome, and one of the complainants claimed he was a teenager when some of the alleged abuse took place.

Saunders had pleaded not guilty to all charges, and has long maintained his innocence.

The case hinged on testimony delivered by Saunders’ three accusers, who said the bishop often invited them to alcohol-fuelled “shirts-off” parties hosted at Catholic Church-owned properties, and he would use wrestling or grappling as a way to get closer to them and attempt to abuse them.

Others claimed the bishop had groomed them by supplying alcohol to them in dry communities, and buying them cigarettes and clothes.

Throughout the trial, Saunders’ former co-workers, including the now Bishop of Geraldton Michael Morrissey, provided evidence about the former bishop and his time in charge of the Kimberley diocese.

Defence lawyer Tony Hager repeatedly went after the memory and criminal history of the complainants, saying they all had abused alcohol in the past and said they had all crossed paths while in the Kimberley’s prison system.

Hager put to one of his accusers they had gotten together to accuse the bishop in order to “stitch him up”.

The conviction makes Saunders one of Australia’s most senior Catholic clerics to be found guilty of sexual abuse, second to only late Cardinal George Pell, who was ultimately acquitted by the High Court of Australia.

More to come.