Khan was charged with the murder of his co-worker, Sarah by stabbing with a knife. The knife was later found buried in a backyard of property occupying by the Khan. The blood sample takes from the knife matches with Sarah. Sarah was reading a letter, includes the warning of the stabbing when the murder occurred. The evidence includes a stabbed knife, the warning letter with blood, and a chat log between Khan and Sarah, a day before the murder. The evidence submitted by the prosecution also includes the sketches and photos of the crime scene, X-rays, and medical examination reports by Dr. Harry, who examines the murdered body. The witnesses against Khan include, a patient of a lunatic asylum, laboring under a delusion that he had several spirits about him which were continually talking to him.

With reference to evidence law, explain the types facts and forms of evidence concerning the given scenario? (15 Marks)