May 1, 2013 earmarks a 10 year period since the adoption of major Acts of the Republic of Lithuania regulating criminal prosecution, namely Act No. VIII1968 or the Criminal adopted on September 26, 2000, Act No. IX785 or the Code of Criminal Procedure and Act No. IX994 or the Code of the Enforcement of Sentences adopted on June 27, 20021. The present article deals with the major elements of and distinctions between pretrial procedures regulated by the old and modern Criminal Codes of the Republic of Lithuania. Other legal Acts, particularly recommendations approved by Prosecutor General's ordinances, are also analyzed. Additionally, the article addresses amendments and modifications to the Code of Criminal Procedure made before midOctober 2013. The survey reveals that during the last decade, 37 amendments and modifications have been made to over 360 articles of the Code of Criminal Procedure. The article specifically focuses on the purpose and models of the pretrial investigation and legal statuses, interaction and results of actual performance of the subjects involved into the process. The summary of the ten year changes in the regulation of the pretrial procedures comes up with the assumption that apart from some positive shifts in the regulation of the criminal procedure, essential changes validating pretrial investigator's greater autonomy and lesser dependence on the prosecution office and a more consistent model of the prosecutor's role mostly preconditioning the poor results of the criminal prosecution are still to be adopted. The article specifies essential problems to be addressed in the procedural regulation of the pretrial stage: a clear determination of the procedural roles of the subjects involved into criminal proceedings (in particular, the roles of the investigator, chief investigator, pretrial investigator and the prosecutor), relevant and optimal correlations of the roles and improvement of the legal status of the aggrieved party.