These days, the common presumption of the courts is that parents will more-or-less share the custody of the children. The idea is that children thrive best when they have a solid relationship with both of their parents.
Most of the time, that's true. There are situations, however, when it's totally appropriate to ask the court for sole custody of your child during a divorce. Here are a few:
Drugs and Alcohol
If your spouse has a problem with prescription drugs, street drugs, or drinking, you may naturally be concerned about his or her ability to properly care for your child. It's also normal to be concerned that your child could accidentally ingest the drugs or alcohol that are all around them.
If your spouse has a serious mental disorder that affects his or her ability to be an effective parent, it may be necessary to shield your child from emotional harm or physical neglect. If your spouse's mental condition makes it difficult to stay in touch with reality or handle his or her own needs, you can't expose a child to that situation.
It doesn't matter if your spouse raised a hand to the kids or just to you. Either way, that could be reason enough for the court to give you sole custody of the kids. Anyone who can't control their temper shouldn't be allowed to be alone with vulnerable children.
Parental alienation occurs when one spouse tries to poison the relationship between the children and the other spouse. For example, your spouse may criticize you to your children, encourage the kids to avoid you, prevent you from engaging with the children on your own time, and otherwise obstruct your attempts to parent. The courts tend to frown very heavily on that kind of behavior and may remove the children from the custody of the parent acting that way.
It's important to provide a stable home for your children. That can be difficult to accomplish when you're facing a criminal trial and possible incarceration. While your spouse may be presumed innocent in criminal court, a judge's first concern is going to be the welfare of any children involved. If your spouse's legal troubles are significant, it may be smartest to keep the children out of the situation.
Do you believe that you have a valid reason to seek sole custody of your child? If so, speak to a divorce attorney who has experience fighting for custody.