The man shot dead by police near Heathrow Airport may have been lost and confused and looking for his mother's home, an inquest into his death has heard.
Keith Larkins was mentally ill says his family.
Keith Larkins, 33, from Feltham, west London, was killed by armed officers after his car had been stopped near the airport last Friday.
Solicitor Louise Christian told the court Mr Larkins' family think he then became distressed and they "have many concerns about his death".
The details emerged at a brief hearing at West London Coroners' Court in Fulham as an inquest was opened and adjourned.
Mr Larkins' car had been stopped by an officer in a police dog van on routine patrol.
The police say when the dog handler went back to his own van to get a raincoat, Mr Larkins drove off.
Mr Larkins, an unemployed security guard, allegedly fired blanks at the officer from a replica police handgun before being shot by officers from an armed response unit.
Miss Christian questioned the police account given to the court by Detective Chief Inspector Ron Knight, who is investigating on behalf of the Metropolitan Police Authority.
"It's very difficult to drive forward and aim backwards," Miss Christian said.
"You appreciate the reason I'm doing this. I just want to convey some of the family's many concerns."
Earlier the court heard a post-mortem examination found Mr Larkins died after being shot twice, once in the chest and once in the stomach.
The family asked for a second examination to be carried out.
The hearing was told the police investigation into the shooting was likely to be "very lengthy".
Coroner Alison Thompson adjourned the inquest to a date yet to be fixed.
Outside the court, Miss Christian said Mr Larkins had recently become mentally ill and a psychiatrist had been due to visit him at home.