(Fairfax County Police)

Fairfax County’s top prosecutor on Friday said he had concluded that a county sheriff’s deputy acted in self defense when he fatally shot a man suffering from apparent mental illness last summer outside Inova Fairfax Hospital.

The August death of Jovany Amaya Gomez — previously identified as Giovanny Martinez — brought renewed attention to use of force by authorities in Virginia’s largest jurisdiction. The county had come under scrutiny after the 2013 fatal shooting of John Geer outside his Springfield home and the death by stun gun last year of county jail inmate Natasha McKenna.

Commonwealth’s Attorney Raymond F. Morrogh said Amaya was killed after charging at sheriff’s deputy Patrick McPartlin with a metal pole, which the 18-year veteran believed to be a sword. Amaya’s agitation, language barriers and mistaken perceptions all contributed to the Aug. 15 incident, Morrogh found.

“As Mr. Gomez turned the corner ... he raised the ‘sword’ and continued advancing” towards McPartlin, Morrogh said in his report, which was based on interviews conducted by Fairfax police and hospital surveillance camera footage.

“Reasonably perceiving himself to be in imminent danger of death or great bodily harm, MDS McPartlin, while retreating, discharged his weapon until the threat was abated,” Morrogh wrote. He ruled the killing justified.

Noe Sanchez Amaya, center to right, Adan Martinez and Orlando Lemus Garcia are relatives to Jovany Amaya Gomez — previously identified as Giovanny Martinez. (Matt McClain/The Washington Post)

While the report means no criminal charges will be filed in the case, it reveals some challenges in how Fairfax County law enforcement officials deal with the mentally ill, particularly those among the county’s growing immigrant population who don’t speak English.

On the sweltering day of the shooting, Amaya, a Honduran national, initially approached a county police officer sitting inside his cruiser off Little River Turnpike in Annandale, according to the report.

Unable to understand the Spanish-speaking immigrant, the officer used his cell phone to call up Google’s language translation application, which helped him determine that Amaya wanted to hurt himself.

The officer had Amaya transported to the hospital with the intention of taking him to the county’s Merrifield Center for mental health treatment if tests showed signs of mental illness.

But a Spanish-speaking nurse said Amaya complained only of a stomach ache and did not appear to want to hurt himself. Amaya was discharged with a doctor’s instructions to return for a follow-up examination.

After a security guard escorted Amaya to a nearby bus stop, he began acting erratically, waving around a pole from a “No Smoking” sign, the report said.

A hospital security guard showed up and Amaya struck him with the pole in the back of the neck. Another security guard responding to the scene told others on his radio that Amaya was carrying a “bladed weapon.”

McPartlin heard that report and, when seeing Amaya waving around the pole, thought that it was a sword.

With his gun drawn, the deputy told Amaya in English to stop and to drop the weapon.

Amaya charged at McPartlin, who fired his handgun, striking Amaya three times in the torso and once in the arm.

Amaya was taken to the hospital emergency room, where he died.