Section 4. Service of process for a civil action brought pursuant to this chapter shall be made upon the attorney general for the commonwealth who shall defend the commonwealth against all such claims. The attorney general shall immediately notify the district attorney for the county that prosecuted the felony that forms the basis for the claim. Any district attorney so notified by the attorney general shall immediately notify any individual meeting the definition of “victim”, as set forth in section 1 or chapter 258B, of the felony conviction that forms the basis of the claim. Any such victim shall be allowed, but may not be compelled, to testify or furnish other evidence. If such victim is unavailable to testify or decides not to testify, his prior recorded testimony, given under oath at a relevant proceeding, shall only be admissible after judicial review and determination that such testimony, or portion thereof, may be helpful to the factfinder. The attorney general shall consult with the appropriate district attorney relative to the merits of such action and, following consultation, shall have discretion to determine whether to proffer as evidence any documents, records, testimony or other information brought forward to the attorney general by such district attorney in defense of the commonwealth at a time deemed appropriate by the attorney general. The attorney general may arbitrate or settle any claim for damages filed under this chapter, but any award or settlement in excess of $80,000 shall be made only with the prior approval of the secretary of administration and finance. The acceptance by the claimant of any such award or settlement shall be in writing and shall, except when procured by fraud, be final and conclusive on the claimant, and shall constitute a complete release of any claim by the claimant against the commonwealth and a complete bar to any action by the claimant against the commonwealth by reason of the same subject matter.