Actus Reus of murder

Write a detailed report which encompasses each of the following tasks:
Task1 : Explain and evaluate in detail the various elements necessary to prove the criminal liability of a defendant accused of murder. Use examples from case law to illustrate your answer.
Task2: Focusing on the Actus Reus of murder, explain the importance of the concept of voluntariness and evaluate the concepts of causation and omissions.
Task3: Evaluate whether the mens rea of murder is adequate or satisfactory, include the problems with proving intention. Cite authorities to illustrate your answer.
Task4: Evaluate in detail whether the law relating to the defences to murder is sufficient or in need of reform. Cite authorities to illustrate your answer.

Note: everything in this assignment should be written within the frames of English Legal System, therefore this assignment will fail if American law is interpreted.
Should be written in form of REPORT