Westminster terror attacker Adrian Ajao reportedly made a dummy run in the days running up to his 82-second bloody rampage.
According to GPS information, terrorist Adrian Ajao, also known as Khalid Masood, travelled in a car over Westminster Bridge just days before he killed four people and injured more than 50.
Last night Scotland Yard refused to comment on its ongoing investigation.
The 52-year-old, who hired a Hyundai 4x4 used in the attack from a branch of rental firm Enterprise in Solihull, visited the scene prior to the attack, according to security sources.
Two security officials told the Wall Street Journal said that GPS tracking of a car used by him showed he drove across Westminster Bridge and approached Parliament on Saturday, March 18.
Days later he conducted the attack, driving into pedestrians killing a mother of two, an American tourist and a south London pensioner before crashing his hire car and stabbing to death Pc Keith Palmer, a 48-year-old husband and father, at the gates to the Houses of Parliament.
His three victims on the bridge were Aysha Frade, a 43-year-old British mother; Kurt Cochran, a US tourist from Utah; and 75-year-old Leslie Rhodes, from south London.
The Islamic State-inspired terrorist had lied to his family that he was flying to Saudi Arabia before disappearing to prepare for the attack.
His secrecy has bolstered the theory he was a “lone wolf” jihadist rather than linked to any terror cell.
Security sources told the paper his movements showed he prepared the attack, rather than making a last-minute decision beforehand.
But his actions also suggests he was not a trained terrorist as he would have conducted the dummy run "on the same day of the week, or at least a weekday, to ensure the security measures and traffic were similar" to the day of the attack, one official said.
Ajao had travelled to Brighton and checked into the Preston Park Hotel on the day before the dummy run.
He checked out the next day to conduct the test run - the same journey he would repeat on Wednesday, March 22.
Ajao returned to the hotel the night before his attack and then spent most of the day in his room and ate a takeout kebab for dinner, before driving to London the next morning and carrying out the attack.
His partner Rohey Hydara this week spoke out after Masood 's mother, Janet Ajao, said she had "shed many tears" for her son's victims.
In a statement released through the Metropolitan Police, Ms Hydara said: "I am saddened and shocked by what Khalid has done. I totally condemn his actions.
"I express my condolences to the families of the victims that have died, and wish a speedy recovery to all the injured."
The terror attack took just 82 seconds before he was shot dead by armed police after fatally knifing Pc Palmer, 48, in the Palace of Westminster's cobbled forecourt.
Separate inquests into the deaths of the killer and his victims began this week.