(1) The department shall issue a certificate to eligible offenders deemed by the department to have successfully completed both the residential and aftercare portions of treatment within the first three years of the eligible offender's term of commitment. The eligible offender may then petition the sentencing court for suspension of the remainder of the term of sentence. Only offenders convicted under 45-9-102 (5) (a) (ii) , MCA, are deemed to be eligible offenders for the purpose of sentence suspension.