Is addressing the issue of sodomy in a criminal investigation and exposing it considered a violation of a Muslim's privacy, or should the focus have been solely on the original issue, which was the brawl?

There is no blame upon you for what you did in referring one who voluntarily confessed to committing indecency to the judiciary; rather, it is obligatory. The Messenger of Allah, peace and blessings be upon him, said: "Forgive each other the prescribed punishments among yourselves, for whatever prescribed punishment reaches me has become obligatory." This applies specifically to one who is not known for harm and evil. However, as for one who habitually engages in such acts, he must be referred to the ruler. Some scholars deemed it recommendable to instruct the accused on what would spare him the prescribed punishment if he was not known for evil and committed the sin as an oversight. This instruction is specific to prescribed punishments related to the right of Allah. As for the police, in their capacity as deputies of the ruler in establishing security, they are not permitted to pardon criminals; rather, they must enforce the prescribed punishments. Whoever among the children has reached puberty is subject to the prescribed punishment, while whoever has not reached puberty is subject to discipline.