The definition of voluntary surrender:

 Voluntary surrender refers to the fact that, prior to the disclosure of the crime, the criminal voluntarily states the course of the offense to the authority of  investigation( e.g. Prosecutors Office, Police Department) or its public officials(e.g. prosecutors, police officers), and accepts the following trial and judgment.

The elements of voluntary surrender:

 Voluntary surrender must be made before the crime is disclosed, which means the authority of investigation or its public officials have not discovered the crime, or have discovered the crime with the suspects unknown. The crime is still not disclosed even though the victims or others are aware of the offenses. To make a voluntary surrender legally valid, the criminal must state the course of his/her offenses, thoroughly from the beginning to the end.  

Voluntary surrender has to be made to the authority of investigation or its public officials, and accepts the trial and judgment. So if the criminal escapes or hides away after surrendering voluntarily, the voluntary surrender does not establish in the legal sense. Furthermore, Voluntary surrender to the victims is also invalid.

The way to surrender voluntarily:

Stating either verbally or in writing are both acceptable. If in writing, the express wording of “voluntary surrender” is not necessary.

To voluntarily surrender personally or by way of others are both allowable. Voluntary surrender directly to the authority of investigation, or indirectly through the authority without investigation power are both agreeable, though the latter of which does not make the voluntary surrender valid until the surrender has reached the authority of investigation.