The most important evidence for this case is the DNA results. The weakness of DNA tests is that they are capable of perpetrating injustice. DNA results focus the whole case on physical evidence. The tests also downplay the considerations of reasonable doubt, quality of police work, and essential elements of a trial, such as the presumption of innocence and motive. The lawyers in O.J. Simpson’s case managed to prove to the jury that DNA results could have been planted or mishandled. Thus, there are high possibilities for the trial court to cast doubt over DNA results.
The fact that John’s DNA results match the crime blood DNA results does not prove beyond reasonable doubt that he is responsible for Sally’s murder. Even though the prosecution can use the DNA results as evidence against John, the defense lawyers may argue that the sample profile could match the profile of many other suspects. This argument is in line with the testimony of Sally’s friend who stated that Sally talked of living around drug addicts and violent gangs.
The facts show that John usually showed disrespect for women and became violent when they turned down his offers. John’s ex-girlfriend testifies that he almost killed her when they broke up. Although this evidence helps show that John is often violent towards women, it does not link his violent actions to the rape and murder of Sally. Jenny testifies that Sally’s arms and eyes showed that someone had been hitting her. This testimony does not lead to a strong conviction that John was the one hitting Sally. Although their relationship was on and off, Sally never complained that John was assaulting her.
The time John finished having dinner with Sally was almost the same time Sally was raped and murdered. John confesses that he argued with Sally before leaving the apartment and driving around for a while. John’s roommate also testifies that John came back to their shared apartment at around 1 A.M. or later. This fact, together with John’s testimony that he was with Sally at around 12 A.M., almost places John at the scene of the crime. The blood sample on the knife that was used to slash Sally matches John’s blood profile. John, however, claims that he only used the knife at dinner with Sally. There is a chance that after dinner, John and Sally engaged in an argument, and John decided to assault Sally.
The defense lawyers may base their argument on the testimonies of John’s roommate and football colleagues that he is a good person and not capable of harming Sally. The defense lawyers could argue that the prosecution coached John’s ex-girlfriend and friends to testify against him. Furthermore, there is no evidence to prove John’s motive to commit murder. The only tangible evidence that the prosecution can rely on is forensic evidence. The criminal justice system is increasingly using DNA test results as conclusive evidence. The court is likely to accept DNA test results that have been properly handled while under police custody. Detective Smith and his colleagues should be able to show that they have not tainted, switched, or subjected the DNA results to any improprieties while under their custody. This may help in proving beyond reasonable doubt that as the DNA results match John’s profile, he committed the crime. I, therefore, back Detective Smith’s belief that John Brown should be arrested for the murder of Sally.