LITTLE ROCK, Ark. (AP) — A pathologist fired from an Arkansas veterans hospital after officials said he had been impaired while on duty pleaded guilty Thursday to involuntary manslaughter in the death of a patient who authorities allege he misdiagnosed.

Robert Morris Levy also pleaded guilty to one count of mail fraud under an agreement with prosecutors, who moved to dismiss multiple other charges against the former pathologist.

Levy was indicted last year on three counts of involuntary manslaughter in the deaths of patients prosecutors said he misdiagnosed. He was also indicted on multiple charges of fraud and making false statements for his alleged attempts to conceal his substance abuse and incorrect diagnoses.

Under the agreement Levy pleaded guilty to misdiagnosing a patient with small cell carcinoma who died after being treated for a type of cancer he didn’t have. Levy falsified the patient’s medical record to state that a second pathologist agreed with his diagnosis, according to the agreement.

Levy also pleaded guilty to one count of mail fraud for receiving 2-methyl-2-butanol, a chemical that he used to intoxicate himself but that standard drug and alcohol screenings don’t test for.

Levy was fired from the Veterans Health Care System of the Ozarks in Fayetteville in April 2018.

VA officials said last year that outside pathologists reviewed nearly 34,000 cases handled by Levy and found more than 3,000 errors or missed diagnoses dating back to 2005. Levy has acknowledged that he once showed up to work at the Veterans Health Care System of the Ozarks drunk in 2016, but he denied that he had worked while impaired. He entered an in-patient treatment program following that incident and returned to work in October 2016 after agreeing to remain sober and submitting to random drug testing.

Levy faces up to eight years in prison and up to a $250,000 fine for the involuntary manslaughter count, and up to $250,000 fine and up to 20 years in prison for the mail fraud count. A sentencing hearing has not been scheduled yet.