Brandon Jackson, brother of Anton Black, and Janell Black, Anton's mother, outside a town council meeting in Greensboro on Jan. 3. (Courtland Milloy/The Washington Post)

A 19-year-old African American man involved in an altercation with police on Maryland’s Eastern Shore suffered “sudden cardiac death,” the state medical examiner concluded about an incident that has roiled the small town of Greensboro.

The medical examiner ruled the death of Anton Black accidental. The autopsy report for Black, signed Wednesday, said it was “likely that the stress of his struggle” with police contributed to his death, as did bipolar disorder and underlying heart issues, but said “no evidence was found that restraint by law enforcement directly caused or significantly caused or significantly contributed” to the Sept. 15 death.

Toxicology tests found no evidence of drugs in Black’s system, the report said.

A statement released Thursday by attorneys for the Black family called for a grand jury investigation and questioned the basis for Black’s arrest and the use of force against him.

“There was nothing accidental about the police conduct here,” according to the statement, which said there was “an intentional and wrongful decision to arrest Anton Black who had committed no crime” and “intentional decisions to use the degree of force” that the family said led to his death.

The statement also said that Black “was no threat to any of them.”

Black died in a physical encounter with police after an officer responding to a call of a child abduction chased, Tasered and restrained Black. Police said Black fled an officer who told him to release the child, which he did.

Black’s family has said the child with Black was a close, longtime family friend, and the father of the younger boy has said that what the caller to police saw was horseplay, not a kidnapping.

The case has thrown the town into the national debate about how African American men are treated by law enforcement.

Caroline County State’s Attorney Joe Riley said Thursday evening that “there is not currently enough evidence to establish probable cause to seek an indictment. There is no intention to place this matter before” a grand jury “at this time.”

Riley explained his reasoning in a statement that acknowledged the tragedy of the death of a 19-year-old while concluding that a prosecutable crime had not occurred. His statement gave details of how he factored in findings by the medical examiner and by the investigating law enforcement agencies about the cause of Black’s death and whether actions of police officers caused the death and, if so, were prosecutable.

His office “remains committed to following the evidence in this matter wherever it leads and will evaluate all evidence that is shared,” his statement also said.

The Black family statement noted that the autopsy report cited dozens of abrasions and contusions on Black’s head, back, arms and legs. The autopsy report said a Taser dart was in his left buttock.

The medical examiner’s report said there was no evidence found, based on the officers’ interviews and the video of the incident, that Black was “physically struck by officers, or had force applied to his neck.”

The family called again for a public release of unredacted police body camera video by the town of Greensboro. Video was shown to the media Wednesday. Riley, the state’s attorney, had directed law enforcement officials not to release the video while the investigation was ongoing but said in his Thursday statement that police agencies were now free to make it public in accordance with their own internal policies.

Black ran to his family’s home and got into a parked car there, where an officer used a baton to break a car window, police have previously said in a statement, and then used a Taser on Black, who then exited the car on the opposite side.

The Greensboro officer had been joined by two off-duty officers and a civilian during the incident, a previous police statement said,

The report from the Office of the Chief Medical Examiner said the video shows an officer lying across Black’s back at one point. Black was put in leg restraints and shortly after, became unresponsive, the medical examiner report states. About 11 minutes after the altercation began, he was receiving CPR, the medical examiner report says. Black was taken to a hospital and pronounced dead , according to the report.

LaToya Holley, Black’s sister, who is 37 and lives in Delaware, said Thursday that Black has “never been diagnosed with any mental illness of any kind.”

The autopsy report states that according to Black’s medical record, “he had recently been involuntarily hospitalized and diagnosed with bipolar disorder.”

In its statement, the family said “the medical examiner performs pathological examinations of the deceased, not mental examinations of the living. In any event, Anton Black did not die because of any mental condition.”

Julie Tate contributed to this report.