D and Z are members of a gang suspected of organizing bank robberies. D and Z plan and execute the robbery of Maxisecure Bank during which they remove a large amount of cash. During the robbery, they flee when a bank teller presses the emergency button and end up at the house of another member of the gang, A. A did not participate in the planning and execution of the robbery but helps D and Z to hide the money in his house and provides them with a place to stay. Following a tip-off, the police arrest D and Z in A's house and manage to find the missing money in A's house. Answer the following questions with reference to this set of facts:

1.1 Fully discuss the competency and compellability of D and Z as witnesses.

1..2 A decides to testify in the case. How must the court approach his evidence?

1.3 During the investigation, Z makes a confession to Sergeant Molokwane, but later disputes the admissibility of the confession. Fully discuss the requirements for the admissibility of the confession and the process that will be used to determine the admissibility of the confession.