I myself am an alcoholic and have had DUI convictions, now many years ago.
I know the terrible stress and hurt that comes from this. The Lord was with me through all my troubles and can be with your loved one too. Let him repent and commit his life to God now in his heart and ask the Lord for deliverance and mercy.
I have been delivered from alcoholism and all its damaging effects and my life restored from it by the power of Jesus. Praise God.
I pray the Lord gives the judge knowledge and softens his heart towards your loved one and that his verdict be merciful and mild. Our Lord controls these things and all things.
And I pray that your loved one would come to have a personal relationship with the Lord and walk in the guidance and wisdom of the Lord forever. And I pray for your loved one's mind and spirit, that he would receive peace and the knowledge of God's hand upon him and his situation now. And that he be protected in the place he's in and be released soon.
And I pray for you also, sister, that you would receive peace and comfort from Father God and that your spirit be healed and strengthened.
The Lord bless and keep you and yours.
In Jesus' name. Amen.