Praise be to Allah.
A person who has killed himself should be washed, prayed over and buried with the Muslims, because he is a sinner but he is not a kaafir. Killing oneself is a sin but it is not kufr. If he killed himself – we seek refuge with Allaah – he should be washed, shrouded and prayed over, but the khaleefah and important people should not pray for him, by way of rebuke, lest anyone think that they approve of what he did. If the khaleefah, ruler, judges, president or mayor do not pray over him in order to denounce this action and announce that it is wrong, then this is good, but some of the Muslims should still offer the (funeral) prayer for him.