Teshuva in Responsa V
In a Responsum (no. 37) on penance, The Rema considers the case of a man who inadvertently pressed the trigger of a gun he was holding, killing his servant.
The Rema rules that it is an accident so that there can be no question of imposing the penance set forth in the work Rokeah for the crime of murder.
Nevertheless, the man should confess his sins and the following penance should be imposed:
He should leave his home for a whole year to wander from place to place, staying no longer than a single day and night in any town.
For a whole year he should fast during the day and confess his sin each night.
The anniversary of the tragic event should be kept each year as a day of fasting and mourning.
But no stricter penance should be imposed. Repentant sinners must not be treated too harshly. God accepts sincere repentance because He desires the life of the sinner, not his death. It is strictly forbidden for anyone to taunt him with the deed, and he himself should confess his sin to God alone and not dwell on it in public.