Although physical child abuse is much more prevalent, the majority of abuse cases prosecuted involve sexual abuse. Society perceives sexual abuse as more horrific and physical child abuse cases, even when successfully prosecuted, result in lenient punishment. Prosecuting physical child abuse is difficult, for several reasons, including society's high expectations for thorough and complete investigations combined with the lowest conditions with which to work. In addition, there is the fine line between child abuse and child discipline. One of the keys to successful investigation and prosecution of child physical abuse cases is for the different agencies involved--law enforcement, children's services, prosecutors, hospitals--to work together. Establishing within law enforcement agencies a specific child abuse unit, with specially trained officers, may also be helpful. The abuse of children with disabilities requires research and increased attention. Evidence shows that those children may be at as much as two times the risk for abuse and neglect. To upgrade investigations and prosecutions it is important to develop standards. Finding out what works and applying it consistently is extremely important when dealing with children and physical abuse.