SECTION 1. Section 6 of chapter 62 of the General Laws is hereby amended by inserting after subsection (k) the following new subsection:-

                   (L) A taxpayer shall be allowed a credit against the tax liability imposed by this chapter, equal to the gross amount of the tuition incurred by the taxpayer if such person is the graduate of a law school that has been approved by the state and the Association of American Law Schools, the American Bar Association, or both and is practicing public interest law within the state. Practice of public interest law shall include but not be limited to, practice at legal services corporations, public defenders offices, district attorneys offices, attorney generals offices and employment with other 501(c)(3) non-profit organizations. If the amount of the credit allowed hereunder exceeds the taxpayer's liability, the commissioner shall treat such excess as an overpayment and shall pay the taxpayer the amount of such excess.