He started in Formula One as a mechanic at Shadow in 1977, then followed Elio de Angelis to Lotus before moving to Benetton for the late 1980s and early 1990s and then to Scuderia Ferrari with Michael Schumacher, Rory Byrne, and Ross Brawn.
On 1 February 2007, it was reported on the Internet that Stepney was unhappy with Ferrari's technical restructuring and that he wanted to leave the team, seeking a new challenge.
[13] Later the same day, Ferrari announced the company was taking legal action against Stepney and McLaren engineer Mike Coughlan.
"[15] Upon his return from holiday in the Philippines on 5 July, Stepney was interrogated by the Italian police as part of the industrial espionage case.
[17] Since the revelation of Coughlan's involvement in the affair, McLaren provided a full set of drawings and development documents to the FIA, detailing all updates made to the team's chassis since the incident occurred at the end of April.
As a matter of good order, the FIA recommends to its licensees that they do not professionally collaborate with Mr. Stepney without conducting appropriate due diligence regarding his suitability for involvement in international motor sport.
"The restriction was lifted on 6 February 2009, with FIA president Max Mosley claiming that Stepney and Coughlan had only been "minor players" in the scandal.
[20] On 29 September 2010, Stepney was sentenced to 1 year 8 months in prison and handed a €600 fine for his part in the spy affair, after being found guilty of "sabotage, industrial espionage, sporting fraud and attempted serious injury".
[27] A subsequent Coroner's inquest "concluded it was a suicide", but also said they had "found no reason for Mr Stepney to take his own life", and recorded an open conclusion.