SAN FRANCISCO — The spectacular rise and fall of health start-up founder Elizabeth Holmes still prompts questions about how it could have happened.

Holmes, who rocketed to fame nearly a decade ago, said she founded Theranos to revolutionize blood testing. But she toppled from grace nearly as quickly after investigations revealed her company’s blood-testing technology was not working as advertised.

She was found guilty Monday on four counts of wire fraud and conspiracy to commit wire fraud amid allegations that she knowingly misled investors about her company’s capabilities. She could face decades in prison.

Her trial began Sept. 8 in federal court in the Northern District of California in San Jose. Here’s what you need to know.