They certainly fit the categorisation of commiting crimes without doubt as to their guilt. Whether that is enough today to take their lives is what you need to convince others of.
If these people may have attempted to take their own lives as well then I think that could be the red flag for capital punishment. If they dont attempt their own demise at the time of murdering their child or in the immediate time after then it is probable that some level of mental incapacity would need to be applied to cases. If they try killing themselves and dont succeed they know they dont deserve air.
