If I have moved out of the home and left the children with the abuser, will this hurt my chances of gaining custody?
Maybe. A judge may consider which parent has been taking care of the children since you moved out as an important factor when making a custody decision. Furthermore, after a parent files a petition for divorce, annulment or separate maintenance, the judge can make an ex parte order regarding the legal custody, residency, and parenting time with the minor children that lasts during the court proceeding.1 It is important to note that the judge is not supposed to issue an ex parte order that changes the residency of the child from the parent who has had, in effect, sole residency of the child unless there is sworn testimony to support a showing of extraordinary circumstances.2 The judge may or may not agree that the domestic violence you experienced is an extraordinary circumstance.
A judge may also consider how long you have been out of the home and that fact that you left your children with someone who is abusive.
1 K.S.A. § 60-1607(a)(3)
2 K.S.A. § 60-1607(b)