The Defense

Once an investigation has ended, it is time to take the case to the court, in order to attempt to prosecute the person suspected of the crime, assuming that the defendant pleaded not guilty. In the court, their verdict will be decided by the Jury, which needs to be convinced to either find the defendant guilty or not guilty. It is the job of the Defence to convince the Jury that the defendant is Not Guilty

The job of the defense lawyers is to work in the best interests of the defendant, and to hopefully have them equipped, and if not to have their sentence reduced. 

They do this by presenting evidence of their own in favor of their clients' innocence, and by undermining, and discrediting any evidenced presented by the Prosecution. They also will do there own investigative work into the case, in an attempt to either find other suspects, or find evidence which proves that their client is not guilty. If this cannot be done, then the defense will often turn to discrediting the evidence provided by the prosecution. 

The OJ Simpson Case

OJ Simpson and Johnny Cochran

Concerning the OJ Simpson case, OJ had arguably the best defensive team that money could buy, in the form of what was dubbed the "Dream Team", why the media.
OJ's defence team consisted of Robert Shapiro, Robert Kardashian, Alan Dershowitz, Lee Baily and the lead attorney Johnny Cochran. 

Johnny Cochran was a keen advocator for black rights and believed that OJ was framed because he was black; which was supported by Mark Fuhrman's racism. 

It was Johnny Cochran who delivered the famous closing argument in which he said "If the glove doesn't fit, you must acquit" 

It was the main argument of the Defense team that Simpson had been set up by racist police officers, trying to 'take down' a successful African American man. Their claimed were supported by the, at the time recent race riots in LA, over Police Racism. There defense grew even stronger when tapes of lead detective Mark Furhman emerged, being heard to be very racist on these tapes.