It comes as a former Met Police chief calls for social media checks for those seeking a gun licence.
Prayer services are to be held in Plymouth on Sunday as the city mourns the five people shot dead on Thursday.
Churches across Devon, including St Thomas’ Church in Keyham, are expected to use their Sunday services to remember the victims.
It comes as questions remain over how gunman Jake Davison, 22, obtained a firearms licence.
A former Met Police chief has said the social media accounts of anyone wanting to possess a gun should be examined.
In the 12-minute attack on Thursday evening, Davison shot his 51-year-old mother Maxine Davison, also known as Maxine Chapman before killing Sophie Martyn, aged three, and her father Lee Martyn, aged 43.
He then killed Stephen Washington, 59, in a nearby park before shooting 66-year-old Kate Shepherd, who later died at Derriford Hospital. He also shot and wounded a 33-year-old man and a 53-year-old woman before turning the gun on himself.
On Saturday Home Secretary Priti Patel paid her respects to the victims by placing a floral tribute near the scene, at North Down Crescent Park, where hundreds of people had attended a vigil on Friday evening.
Chief Constable of Devon and Cornwall Police Shaun Sawyer also laid a bouquet.
The home secretary and Plymouth Sutton MP Luke Pollard then spoke to members of the local neighbourhood watch team at the park.
Later, the Anchorage pub in Plymouth, where Lee Martyn was a regular, held a two-minute silence.
Head chef Sam Weight said staff were “all really upset” about the deaths. “Lee and Sophie were a pair and he was an absolutely amazing dad, he would do anything for her,” she said.
“He was always joking and she was a cracking little kid who had not even started her life.”
And Claire Kidd paid tribute to her “very talented artist” friend Kate Shepherd, who lived in Kingsand, Cornwall, before moving to Plymouth.
“We are all feeling deeply sad and in shock,” she added.
Police are not treating the incident, the worst mass shooting in Britain since 2010, as terror-related.
However, Davison had made references to “incels” – members of misogynistic online groups of “involuntary celibate” men, who blame women for their sexual failings and who have been linked to a number of violent acts around the world – in some online social media videos.
Former commissioner Lord Stevens told the Sunday Telegraph Davison was “clearly a dangerous man”, adding: “The videos he made should have been taken into account when he applied for a shotgun licence.
“There needs to be a trawling of online content for an in-depth assessment of who these people are and what they think.”
However, Sir Peter Fahy, a retired chief constable and former policing lead on the prevention of terrorism, defended the UK’s firearms licensing system, saying that about 30 people a year were murdered with guns and nearly all of them involve illegally owned weapons.
He added that police and government might need to re-examine definitions of terrorism as the threat from jihadist groups appears to diminish and other threats grow.
The police watchdog is already investigating why Devon and Cornwall Police returned Davison’s shotgun and firearms licence in July, after they were removed at the end of last year following an allegation of assault in September 2020.
- Police forces issue shotgun and firearm certificates
- Anyone who wants to own a gun has to show they have a “good reason” for doing so, for example for use in their job or sport
- Independent referees provide confidential character statements about the applicant’s mental state, home life and attitude towards guns
- Police check for a criminal record and speak to the applicant’s GP for evidence of alcoholism, drug abuse or signs of personality disorder
- Applicants must show they have a secure location for the weapon, typically a dedicated gun cabinet. Each certificate is valid for five years
- Police can revoke certificates if they conclude that the holder can no longer be trusted
On Friday, Prime Minister Boris Johnson has called for the issue of how Davison came to legally own a gun to be “properly investigated” and described the shooting as an “absolutely appalling” incident.
Devon and Cornwall Police said on Saturday that an online page has been launched for those who may have information to assist with the investigation into the mass shooting, the worst in Britain since 2010.
The force added that post-mortem examinations are taking place and due to continue into early next week.