The sun had only recently risen over the roof of Tamworth police station when the white, dark-windowed bus arrived.

One by one about 30 officers filed on and settled in for a six-hour journey that they hoped would end with justice for a fallen comrade and perhaps a small measure of closure for those left behind.

Eight hours and 400 kilometres later, a NSW Supreme Court Justice gave the family, friends and colleagues of murdered police officer Senior Constable David Rixon the result they desired - a life sentence for the man responsible for his death.

In a landmark decision, Michael Alan Jacobs, 49, became the first person sentenced to life in prison under new laws requiring a mandatory life sentence for anyone who murders an on-duty police officer in NSW.