Christopher Koani has been sentenced to life behind bars for the shooting murder of his girlfriend, more than two years after he was initially found guilty.

A Brisbane Supreme Court jury took two hours on Friday to find the 34-year-old guilty of murder for the second time, after the High Court quashed his original conviction.

Koani killed Natalie Leaney with a single gunshot to the head in their Logan unit on March 10, 2013.

He had been found guilty of the same charge in November 2015, but he appealed against the conviction in the Queensland Court of Appeal.

When that was unsuccessful, he took the case to the High Court.

In August 2017, it unanimously ruled the appeal should be allowed.

It also ordered his conviction be quashed and the matter re-tried.

Koani admitted the manslaughter of Ms Leaney on the opening day of the new trial on Monday, but the Crown did not accept his plea and continued with the murder charge.

He had also tried to plead guilty to the lesser charge during his initial trial.

AAP