I haven't paid much attention to the Michael Jackson case. He has become such a freak show in the last 15 years or so that people tend to forget what an enormous talent he was in the 80s, but I haven't paid him much mind in a very long time. The occasion of his not-guilty verdict makes three observations apt.
First, as we've now seen with Jackson, O. J., Robert Blake, Kobe Bryant, and some others I'm probably forgetting, it can be very difficult for local prosecutors' offices to convict celebrities. The cult of celebrity is surely a factor in this, but it is not the most important factor -- not by a long shot. The salient thing is resources.
The local DA's office is where the rubber meets the road of everyday law enforcement. It is equipped to investigate and prosecute run of the mill crime, over 90 percent of which is settled by lesser charges in plea bargaining because the system cannot afford trials -- DA staffs are small, as are local police departments, and if major resources have to be thrown into investigating any one case, other things (like normal policing) feel the pinch, which is understandably unacceptable to the community.
Celebrities, unlike other defendants, can match the prosecutor dollar-for-dollar and then some. They bring in big-time legal talent and first-rate private investigators (who were often top-flight federal or state cops in their earlier lives). It is a big advantage and it is not something that local law enforcement is used to dealing with. I was very lucky to work in the Justice Department, with the FBI and other federal agencies. It wasn't that we were better -- a lot of these state officials are old pros and top-shelf at trial work. It's that DOJ would never be outspent or out-resourced. That's why the feds can take on the Enrons, the mafia dons and the cartel kinpins awash in drug money.
Second is the nature of trials in general. When a case is very serious, juries will accept some level of unsavoriness about the prosecution's witnesses -- as long as the prosecutor doesn't pretend that his witnesses, who are often flawed people and who may be testifying in pursuit of leniency or money, have suddenly transformed into Mother Teresa. But to convict a celebrity you've got to have two things: (a) the evidence needs to be strong, because the defense team is going to be good and is going to expose every weakness in it; and (b) the prosecution needs to avoid that tipping point where the unsavoriness of its witnesses overtakes the seriousness of the charge.