Legal Question in Family Law in California

The wife did not break any law. Without knowing all the details about the family situation and the break-up, I can't say whether or not your brother would have problems getting custody. Being unemployed should not be a barrier to him getting custody at all. The wife's conduct in keeping the children from their father will cut against her unless there is some reason that is in the best interests of the children for doing so (domestic violence cases being an example but not the only basis). Some form of joint custody and shared visitation times is highly favored. Sole custody with no contact with either parent is reserved for abandonment and unfit parent situations, such as domestic violence, mental illness, incarceration, etc. Otherwise a transition from married parents to unmarried but involved and cooperative parents is highly favored by the courts and Family Court Services. Being the parent who shows that he wants what is best for his kids, not to punish his wife, and wants the kids to have a solid relationship with both parents with frequent and regular time with both, will go a long way toward getting a favorable custodial arrangement.