FM, I didn't say I think it should take any specific amount of time. What I said is that ensuring the rights of the accused takes time. Have you ever seen a case go from arrest to conviction to sentencing? I have, and it doesn't happen quickly because of all the things involved. The example you gave has the accused admitting guilt, but you don't specify at what point in the process he admits guilt. Is it at the beginning, when the initial plea is entered, which, at that point wouldn't involve bail because bail isn't granted to people who plead guilty at their first hearing (which almost NEVER happens because plea deals take time to negotiate).
Do you have any idea of how backed up criminal courts are? The court dates in the case I posted about took weeks and even months in between, because of how backed up the court is in this county, and the probation department, which had to provide pre and post sentencing reports. That's just the reality of our justice system, and this was a case in which a plea deal was negotiated. Had it gone to trial, it would have easily been another 3-6 months.
Justice isn't a fast process in this country, and it's because the accused have rights. They have the right to bail. They have the right to competent representation, even if they can't afford to pay for it. They have the right to negotiate the terms of plea deals, if they choose to plead guilty. They have the right to challenge each and every piece of evidence against them, how it was collected, how it was handled. Things like DNA tests, processing evidence, hiring expert witnesses, etc., etc. all take time. As I've already posted, all these rights exist because our system is based on the premise of innocence until proven guilty, even when there are nine witnesses, surveillance footage, incriminating statements by the accused, and rock solid physical evidence. All the things you mention are reasons for the accused to accept a plea deal to avoid losing at trial and getting more time in prison, not reasons to deny the accused due process.