'Too dangerous to set free': Serial killer to remain under supervision

"Cowboy killer" Regina Arthurell will be supervised for another two years after a Supreme Court judge found it would be far too dangerous to set her free.

Arthurell was jailed as Reginald but began transitioning after serving almost 24 years behind bars for bashing to death fiancée Venet Mulhall at Coonabarabran in 1995.

She was on parole at the time, having killed her stepfather and a sailor in the 1970s and '80s.

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The state was seeking a three-year order but was today granted two.

"In light of the established pattern of fatal harm being repeatedly inflicted by the defendant that began approaching 50 years ago, for her to be completely at liberty in the community would simply be far too dangerous," Justice Richard Button ruled.

That was despite conceding the 75-year-old was in poor physical health.

"A frail, even physically disabled, person can inflict fatal harm once armed with a weapon," Justice Button said.

Arthurell will be subject to 47 conditions, which include electronic monitoring and alcohol rehabilitation.

"The defendant, as I have said, is leading a very difficult, lonely life," Justice Button said.

"It is not unrealistic to think that she might begin to seek solace in alcohol, with potentially disastrous consequences."