See, there's a problem with that line of thinking. The US Constitution has safeguards against summary judgement against people ACCUSED of crimes. The 1964 Miranda ruling not only safeguards a suspect's Constitutional rights under the 4th, 5th, and 14th Amendments, but also can work to the prosecutor's advantage. This is why we have due process.
A person is arrested either by probable cause or warrant
His case goes before a Grand Jury, which does not decide guilt, but simply determines whether there is enough evidence to return a "True Bill" of indictment, a formal declaration of charges against a criminal defendant.
Then the case goes before the trial judge and Petit Jury. That trial does determine guilt, innocence, and in a capital case, sentence of death or life without parole.
If the defendant is found not guilty, another Constitutional protection is activated, known as Double Jeopardy. This means that the government doesn't get a second bite of that apple.
Plea deals are often worked out for a plethora of reasons, but the result is usually the same. Defendant stands convicted.