A 31-year-old man suffering a medical or mental-health emergency died Tuesday after Fairfax County police took him into custody at a home in the Alexandria area following a 911 call, police said.

The incident began shortly after 4:30 p.m. Tuesday when officers responded to the 4300 block of Mission Court for a report of an overdose, Fairfax County police chief Edwin C. Roessler Jr. said at a Wednesday news conference.

Officers found a family member of the deceased, Christopher Paul, outside the home, Roessler said. Paul, who had struck the family member in the head, was inside the home, naked and unarmed.

The first two officers who went inside found Paul actively trying to harm himself and tried to de-escalate the situation by talking with him, Roessler said. The officers had received training to deal with people suffering mental-health episodes.

Paul then fell to the floor of his own accord and the officers used the opening to restrain him with handcuffs and a nylon leg restraint, Roessler said. The officers called in Fairfax County Fire Department medics who were staged outside to care for Paul.

Paul soon became unresponsive and the medics began treating him and transported him to the hospital, where he died, Roessler said.

The investigation into the incident is still unfolding, so Roessler said he was not able to give a detailed description of the encounter between the officers and Paul, a timeline of the events or a sense of what caused Paul to become unresponsive. Roessler was emphatic that officers were not violent with Paul at any point.

Roessler said “no physical use of force was used against Mr. Paul” and no weapons were used by the officers.

Roessler said six officers have been placed on routine administrative leave as the department conducts criminal and administrative investigations into Paul’s death. The medical examiner will determine his cause and manner of death.

Roessler said one of the officers involved in the response was wearing a body camera during the incident, but he said the department would not immediately release the footage because it was sensitive to the investigation. He said he plans to release the video at some point.

Roessler said officers did not call for either of the county’s Mobile Crisis Units, which help respond to people in the community suffering from mental-health crises, saying the situation rapidly unfolded.

Training for police officers and sheriff’s deputies handling the mentally ill has been in the spotlight in Fairfax County in recent years, following the high-profile police shooting of John Geer in 2013 and the death of Natasha McKenna at the jail in 2015.

Both incidents prompted officials to seek greater training for officers. An additional Mobile Crisis Unit was added to the county fleet to help the mentally ill after changes were approved in the aftermath of Geer’s shooting.

A man who answered the phone at a number for a Paul relative said the family would not comment. Other relatives did not return calls or messages for comment.