A Nigerian national has been charged with hacking Los Angeles County email accounts that could have compromised close to 800,000 individuals in relation to 15 county departments.

In May, an email phishing attack hit, targeting L.A. county employees. The Los Angeles County District Attorney’s Cyber Investigation Response Team (CIRT) launched a long and complex investigation into the phishing scheme. The District Attorney’s office announced on Friday that of the 1,000 county email users that received the phishing message, 108 were actually affected.

County officials have stated that some of the county employees affected, those that provided usernames and emails through the phishing email, had “confidential client/patient information” in their accounts, according to the Los Angeles Daily News. Forensic investigation revealed up to potentially 756,000.

Austin Kelvin Onaghinor, 37, is charged with nine counts in connection with the intrusion. Those charges include unauthorized computer access and identity theft in a felony complaint. If convicted he could face a sentence of up to 13 years in state prison.

More are still being sought in connection with the case, according to the Daily News. The D.A.’s CIRT is still investigating.

“My office has devoted significant resources to developing cutting edge expertise and relationships that allow us to hold transnational cybercriminals accountable,” said District Attorney Jackie Lacey. “My office will work aggressively to bring this criminal hacker and others to Los Angeles County where they will be prosecuted to the fullest extent of the law.”

Though no evidence has yet been found indicating that confidential information was released, on Thursday officials began notifying those whose personal information may have been compromised. Deputy District Attorney Donn Hoffman remarked on the “time-consuming process” of investigating these types of cases.

Onaghinor has not been arrested and is not believed to be on American soil.

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