The police watchdog said the pair were not present when the raid happened.
It is believed the couple married last year and were expecting a baby girl, which was due on Valentine’s Day.
‘Very much in love’
The family of the pair said the couple were “very much looking forward to the birth of their daughter”.
They had already picked out Sienna Marie as her name, they said.
A family statement said: “Patrick and Shauna were a young couple who had recently got married and were very much in love.
“Patrick was a devoted husband to Shauna and they were very much looking forward to the birth of their daughter Sienna Marie who was due to be born on Valentine’s Day.”
Officers had been pursuing a Renault Scenic for about 10 minutes but terminated the pursuit prior to the crash, The Independent Office for Police Conduct (IOPC) said.
A police helicopter was monitoring the progress of the Renault when it crashed, it added.
“It has now been confirmed, as part of a separate police investigation, that the occupants of the Renault were not present at the time of an aggravated burglary reported to have taken place in Harrow”, the watchdog said.
IOPC regional director Jonathan Green said further investigations would examine the information the police had and the rationale for the pursuit.