RIVERHEAD - Opening statements were heard in Riverhead Tuesday in the trial of a nursing home worker accused in the death of a patient.

Aurelia Rios, 72, was in the Medford Multicare Center's ventilation unit and was supposed to be on a ventilator in 2012. Prosecutors say respiratory therapist Kethlie Joseph, 63, of Brentwood, neglected her duties and did not connect Rios' ventilator.

Prosecutors say Joseph then ignored alarms that Rios’ life signs were fading before her death.

Attorneys for Joseph challenged the accusations, saying that she followed all of the doctor’s orders. They said that some of the alarm technology in the nursing home was not working properly.

She's charged with criminally negligent homicide.

A total of nine people were charged in connection to Rios' death. Two have already taken plea deals.