SECTION 1.  Notwithstanding any general or special law to the contrary the policy relative files under the control and in the possession of the commonwealth and law enforcement shall be that all such files shall be open to defense counsel in their entirety.  The procedure shall be as follows:

(a) Upon motion of the defendant, the court shall order the commonwealth to

(1) Make available to the defendant the complete files of all law enforcement and prosecutorial agencies involved in the investigation of the offenses committed or the prosecution of the defendant.

i. The term "file" shall include the defendant's statements, the codefendants' statements, witness statements, investigating officers' notes, results of tests and examinations, or any other matter or evidence obtained during the investigation of the offenses alleged to have been committed by the defendant. When any matter or evidence is submitted for testing or examination, in addition to any test or examination results, all other data, calculations, or writings of any kind shall be made available to the defendant, including, but not limited to, preliminary test or screening results and bench notes.

ii. The term "prosecutorial agency" includes any public or private entity that obtains information on behalf of a law enforcement agency or prosecutor in connection with the investigation of the crimes committed or the prosecution of the defendant.

iii. Oral statements shall be in written or recorded form, except that oral statements made by a witness to a district attorney outside the presence of a law enforcement officer or investigatorial assistant shall not be required to be in written or recorded form unless there is significantly new or different information in the oral statement from a prior statement made by the witness.

iv. The defendant shall have the right to inspect and copy or photograph any materials contained therein and, under appropriate safeguards, to inspect, examine, and test any physical evidence or sample contained therein.

(2) Give notice to the defendant of any expert witnesses that the commonwealth reasonably expects to call as a witness at trial. Each such witness shall prepare, and the commonwealth shall furnish to the defendant, a report of the results of any examinations or tests conducted by the expert. The commonwealth shall also furnish to the defendant the expert's curriculum vitae, the expert's opinion, and the underlying basis for that opinion. The commonwealth shall give the notice and furnish the materials required by this subsection within a reasonable time prior to trial, as specified by the court.

(3) Give the defendant, at the beginning of jury selection, a written list of the names of all other witnesses whom the commonwealth reasonably expects to call during the trial. Names of witnesses shall not be subject to disclosure if the commonwealth certifies in writing and under seal to the court that to do so may subject the witnesses or others to physical or substantial economic harm or coercion, or that there is other particularized, compelling need not to disclose. If there are witnesses that the commonwealth did not reasonably expect to call at the time of the provision of the witness list, and as a result are not listed, the court upon a good faith showing shall allow the witnesses to be called.  Further in the interest of justice, the court may in its discretion permit any undisclosed witness to testify.

(b) If the commonwealth voluntarily provides disclosure, the disclosure shall be to the same extent as required by subsection (a) of this section.

(c) Upon request by the commonwealth, law enforcement or other prosecutorial agency shall make available to the commonwealth a complete copy of all files related to the investigation of the offenses committed or the prosecution of the defendant for compliance with this section and any disclosure.  All public and private entities that obtain such information shall ensure that all material listed in paragraph (1) of subsection (a) of this section is fully disclosed to the appropriate district attorney for disclosure to the defendant.

(d) Any person who willfully omits or misrepresents evidence or information required to be disclosed pursuant to paragraph (1) of subsection (a) of this section, or required to be provided to the commonwealth pursuant to subsection (c) of this section, shall be punished by imprisonment in a jail or house of correction for not less than 1 nor more than 2 years. Any person who willfully omits or misrepresents evidence or information required to be disclosed pursuant to any other provision of this section shall be punished by imprisonment in a jail or house of correction for not less than 6 months nor more than 1 year.