Suspected criminals and persons undergoing criminal trial (accused) have fundamental human rights to due process/ fair hearing, to dignity and to a speedy trail. They are entitled to pretrial disclosure that enables them to know the precise case against them. They often need to apply for bail. They need adequate opportunity, time and facilities to defend themselves.
Their presence at trial is a constitutional right. While at it, they need to lead witnesses in their favour and cross examine witnesses against them. They must test the admissibility of evidence and the judicial officer deciding their fate should be competent, impartial and free of bran.
Having an experienced lawyer will go long way in securing these basic rights for the accused who in many cases neither know about them nor how to release them.