The 6th Amendment
You get a free trial no matter what
No matter what cops see
No matter what a cop sees they have to let you prove yourself not guilty. It doesn't matter if they see you with evidence of the crime it is the law to let you prove your innocence. You have the opportunity to get a lawyer to help you in a trial.
COPS HAVE THE RIGHT TO ARREST YOU BUT YOU ARE NOT CONVICTED UNTIL GIVEN A FAIR TRIAL
You can be handcuffed if cops identify you as a suspect.
It's not only up to you and your lawyer its up to the jury and the judge.
When you go to court you have to get ready to prove yourself not guilty. Make sure you are ready with quotes and evidence to support why you are not guilty.