Mass. Gen. Laws ch. 108A, § 13: Liability of partnership for wrongful acts of partners

Section 13. Where, by any wrongful act or omission of any partner acting in the ordinary course of the business of the partnership, or with the authority of his co-partners, loss or injury is caused to any person, not being a partner in the partnership, or any penalty is incurred, the partnership is liable therefor to the same extent as the partner so acting or omitting to act.