Mass killer Jake Davison had been reported to the Government's counter-terrorism Prevent programme by his own mother months before he applied for a shotgun licence, an inquest heard.
The 22-year-old spree killer's mother, Maxine, 51, had contacted the multi-agency scheme, which aims to stop people becoming terrorists, in November 2016 with concerns about her son.
Details of the referral were not disclosed during a pre-inquest hearing at Plymouth Coroner's Court but will be a key area of examination in the inquest which will begin in January next year.
Davison killed his mother after a row and then shot dead four others in a 12-minute attack.
Three-year-old Sophie Martyn; her father, Lee, 43; Stephen Washington, 59; and Kate Shepherd, 66, all died on the evening of August 12 last year in the Keyham Devon.
The apprentice crane operator then turned the pump-action shotgun on himself before armed officers reached him.
The killings happened just weeks after the shotgun and licence had been returned to him by Devon and Cornwall Police. They had been seized last year after Davison assaulted two teenagers in a park.
The Independent Office for Police Conduct (IOPC) is investigating how the force approved his application and then later gave him back the licence and shotgun.
Davison applied for a shotgun certificate in July 2017 and after the application was processed by the force a certificate was issued to him in January 2018 that was valid for five years.
As part of the investigation, two members of staff in the firearms licensing department involved in the granting of the shotgun certificate have been served with gross misconduct notices, while an officer has been served with a misconduct notice.
Ian Arrow, senior coroner for Plymouth and South Devon, explained how the inquest would consider how Davison's application for a shotgun was processed by the police, how the allegations of assault against him were dealt with and his referral to the pathfinder scheme.
The inquest would consider the seizure of his shotgun and licence and return a few weeks before the shootings.
Davison's contact with mental health services in May 2021 would be examined and a later occupational health assessment.
The inquest would also consider the events of August 12, Mr Arrow said.
Social media usage by Davison suggested an obsession with "incel" culture, meaning "involuntary celibate", as well as an interest in guns and the US.
Reports have suggested Davison's mother had been struggling to get help for her son, having become concerned about his mental health.
A further pre-inquest review will take place on December 19.
