Mary “Missy” Cummings, an engineering professor at George Mason University, told jurors in Miami federal court that the Tesla owner’s manual, which contains critical warnings about how the system

A critical voice took the stand Wednesday in the first-ever federal jury trial involving Tesla’s Autopilot system: a safety expert who says the technology is defective and promoted in ways that encourage misuse.

A rare trial against Elon Musk's car company began Monday in Miami where a jury will decide if it is partly to blame for the death of a stargazing university student after a runaway Tesla sent her flying 75 feet through the air and severely injured her boyfriend.