Security software pioneer John McAfee was found dead in a Spanish prison cell shortly after Spain agreed to extradite him to the United States. Spanish authorities ruled his death a suicide.

The 75-year-old founder of McAfee Antivirus faced charges of tax evasion. The U.S. Government alleged that McAfee didn’t file taxes for four years, despite earning millions of dollars. But those weren’t the only legal troubles for McAfee. He fled Belize when police attempted to question him about the death of his neighbor.

McAfee also faced charges of fraud and money laundering for his party in a cryptocurrency scheme.

It was a sad end for the tech pioneer who founded McAfee Associates in 1987. He was the first to bring widespread awareness about the dangers of computer viruses to the home user and amassed a $100 million fortune.

McAfee has not been involved with the security company he founded since 2009.