I wish it were that easy Chemaster! We've seen from experience that , in almost every case, minor children remain in the care (if you can call it that) of the killer , sometimes for years, before he/ she is finally brought to justice.
People who are capable of murdering their children's mother are not emotionally well. They are not capable of good parenting; their specialty is emotional and mental manipulation and abuse, which can do nothing but damage to a vulnerable child's psyche.
I am married to a career cop, and believe me, there are many, many children who cops see every day who are not safe in their homes, and there is nothing they can do about it because knowing that the abuse is likely to occur is not enough...the courts don't step in until the damage is done, or a child is dead.
Children are not ever safe with a killer...leaving them there is a roll of the dice. (JMO as well.)