Re: 18 months he has been held ...
Because taking a long time works in the prosecution's favor. It makes the defendant much more likely to agree to a plea bargain, which is how most successful prosecutions end. It makes it less likely the defendant will gain sympathetic mention in the press by the time the case goes to trial, if it ever does. It saps the defendant's resources.
Under the US adversarial system, the prosecution's job is not to seek the truth or achieve justice; it's to secure a conviction or a guilty plea. I've known some prosecutors, in various positions, who were actively concerned with justice - but it's not a job requirement.
Biting the hand that feeds IT
