Md. Code, Health - General § 20–110

(a) Except as provided in subsection (b) of this section, the following are not civilly liable for taking a blood sample from an individual without consent of the individual or for testing the blood sample, if the blood is taken at the request of a police officer or a sheriff or officer in a sheriff’s office for a criminal investigation:

(1) A licensed hospital.

(2) A physician.

(3) Any of the following who take the blood in the course of duties at a licensed hospital:

(i) A resident.

(ii) An intern.

(iii) A registered nurse.

(iv) A health career technician.

(b) A person who negligently takes blood samples in a manner otherwise than according to accepted medical practices or who negligently performs tests is subject to civil liability for injury resulting from the person’s negligence.