An investigation has been launched into an in-custody death that happened while a man was being detained following an altercation at a downtown San Diego bar Saturday night.

A man accused of causing a disturbance inside a San Diego bar, then striking and biting a security guard, died after he stopped breathing while struggling with the guard and then officers, law enforcement said Sunday.

Investigators allege the man was involved in disturbance and struggled with security staff and police officers Saturday night at Star Bar on E Street

Officers responding to reports of an altercation and gunfire at a residence in the 1600 block of Chalcedony Street about 10:15 p.m. Sunday found 31-year-old Richard Herrman outside the condo with a gun, according to the San Diego Police Department.

In adherence to the Countywide Memorandum of Understanding, the San Diego County Sheriff's Office Homicide Unit is leading the investigation into the circumstances of this in-custody death. The investigation is ongoing, with detectives actively collecting evidence, conducting witness interviews, and analyzing the specific events that transpired.

Sheriff's deputies say the man became unresponsive after being restrained by a security guard and police officers.