US President Barack Obama will not intervene in the Troy Davis capital punishment case which has sparked protests, because it is "not appropriate" to become involved in specific state cases, a spokesman said Wednesday. "President Obama has worked to ensure accuracy and fairness in the criminal justice system, especially in capital punishment cases. However, it is not appropriate for the president of the United States to weigh in on specific cases like this one, which is a state prosecution," Press Secretary Jay Carney said ahead of the planned execution.