The medical examiner who performed the autopsy on Eric Garner testified Wednesday that the man’s death was a homicide caused by a “lethal cascade” of events beginning with a NYPD officer’s chokehold, The New York Times reports. Floriana Persechino said NYPD Officer Daniel Pantaleo choked Garner with enough force that, combined with the compression of the man’s chest at the time of arrest on Staten Island in 2014, it set off a fatal asthma attack and left internal bleeding in his neck. “The chokehold is a significant initial factor of the cascade,” she said during Panaleo’s long-delayed disciplinary trial. The officer, who denies any wrongdoing, could lose his job if he is found to have recklessly used the chokehold or intentionally restricted Garner’s breathing. Garner’s death sparked nationwide protests after a video showing his final moments—along with his last words, “I can’t breathe,”—went viral. A Staten Island grand jury previously declined to indict the officer on criminal charges.