Maryland, like all states, holds the best interests of the child to be the primary concern when making decisions relating to custody. The law also maintains that the natural connection that children have to their biological parents is worthy of preservation when it is consistent with those best interests. However, in cases where the parent has demonstrated themselves to be violent, abusive, habitually criminal or otherwise dangerous to the child, the court may be forced to exercise their prerogative to limit, suspend or revoke parental rights.
Any evidence of abuse against the other parent, the other parent's spouse, a child living with them or any other close member of the family may cause the judge to revoke or limit custody and visitation. The custody or visitation order will be decided in such a way that the child and any abused parent is protected.
A parent who has been convicted of murder will usually lose custody and visitation rights. The court may choose to allow supervised visitation in such cases. The emotional well-being of the child will be the deciding factor.
Child custody issues are known to be some of the most difficult issues that the court can face. The best interests of the child can only be approximated in many cases, and the court must weigh any number of opposing factors. It should be noted that where the best interests lie may require a judgement call, and the court is within its rights to use its discretion and make decisions based on the totality of the evidence presented. An attorney may be helpful to a parent who wishes to appear before the judge and make a case for what the best interests of the child.
Source: Women's Law, "Can a parent who committed domestic violence get custody or visitation?", December 17, 2014