Section 4. Any citizen of the United States who is a resident of the judicial district or who lives within the judicial district more than fifty per cent of the time, whether or not he is registered to vote in any state or federal election, shall be qualified to serve as a grand or trial juror in such judicial district unless one of the following grounds for disqualification applies:—

1. Such person is under the age of eighteen years.

2. Such person is seventy years of age or older and indicates on a juror summons response an election not to perform juror service.

3. Such person is not able to speak and understand the English language.

4. Such person is incapable, by reason of a physical or mental disability, of rendering satisfactory juror service. Any person claiming this disqualification must submit a letter from a registered physician stating the nature of the disability and the physician's opinion that such disability prevents the person from rendering satisfactory juror service. In reaching such opinion, the physician shall apply the following guideline: a person shall be capable of rendering satisfactory juror service if such person is able to perform a sedentary job requiring close attention for six hours per day, with short work breaks in the morning and afternoon sessions, for three consecutive business days. If, according to the aforementioned guideline, a person shall be permanently incapable of rendering satisfactory jury service during the person's lifetime, the person claiming such permanent disqualification shall submit a letter from a registered physician stating the nature of the disability and the physician's opinion that such disability will permanently prevent the person from rendering satisfactory jury service. If the jury commissioner determines that the person is permanently disabled, then the person shall be considered permanently ineligible for jury service, and the person's name and physician's letter shall be placed on record with the office of jury commissioner. The jury commissioner shall make a decision on such matter promptly upon receipt of the aforementioned letter. For the purposes of this section, ''physician'' shall include any accredited Christian Science practitioner.

5. Such person is solely responsible for the daily care of a permanently disabled person living in the same household and the performance of juror service would cause a substantial risk of injury to the health of the disabled person. Any person claiming this disqualification must submit a letter from a registered physician stating the name, address, and age of the disabled person, the nature of the daily care provided by the prospective juror, and the physician's opinion that the performance of juror service would cause a substantial risk of injury to the health of the disabled person. Any person who is regularly employed at a location other than that of his household shall not be entitled to this disqualification.

6. Such person is outside the judicial district and does not intend to return to the judicial district at any time during the following year.

7. Such person has been convicted of a felony within the past seven years or is a defendant in pending felony case or is in the custody of a correctional institution.

8. Such person has served as a grand or trial juror in any state or federal court within the previous three years or the person is currently scheduled to perform such service. Any person claiming this disqualification must submit a letter or certificate from the appropriate clerk of court or jury commissioner verifying such prior or pending juror service unless such service was performed or is pending in a court of the commonwealth.