MOST HELPFUL ANSWER 10 POINTS. How do i subpeona someone's police criminal record in QLD?

i AM GOING 2 FAMILY COURT NXT MONTH IN qld. Does anyone know the process to subpeona my ex partners criminal history and what forms do i need to do this? It is very urgent as he is unfit and i cant trust him to have the children as he is very unstable but i need the evidence to support this with his criminal history.