A 46-year-old security guard who died Jan. 28 following a struggle with a shoplifting suspect in Waikīkī died of a heart attack, and the city medical examiner has determined that the manner of death was a homicide.

Frank Rodrigues, a loss prevention officer at DFS Galleria Waikiki, died after he and another security guard attempted to subdue a man who was suspected of shoplifting at the store the day before. After the man was brought under control, police said, Rodrigues sat on a sofa and then became unresponsive.

Rodrigues, an 18-year employee of the company, was taken to the hospital, where he died. Police initially classified the case as an unattended death pending the outcome of an autopsy.

The medical examiner's office said Rodrigues suffered a heart attack. Contributing factors to his death were arterial stenosis and the struggle with the assailant, the medical examiner said.

The suspect, who was arrested on suspicion of a misdemeanor assault against the other security guard, was released from custody without charges pending further investigation, according to the city prosecutor's office.