Police have identified a young woman who was shot dead by her toddler son in a supermarket, after he reached into her purse and fired a concealed handgun.

Officials said Veronica Rutledge, 29, was shopping in the Walmart store in Hayden, Idaho, with the two-year-old and her three daughters when she was shot and killed shortly after 10am.

The toddler had been placed in a shopping trolley’s child-seat and was able to put his hand into Mrs Rutledge's purse. She died before the emergency services could reach her, police said. Officers used the store's CCTV footage and witness testimonies to conclude the shooting was an accident.

They said the Mrs Rutledge had a licence to carry a concealed weapon but it was unclear why the gun went off so easily when squeezed by a toddler, and whether a safety catch was engaged.

The victim's father-in-law, Terry Rutledge, told the Associated Press that the mother-of-four "was a beautiful, young, loving mother".

"She was not the least bit irresponsible," he said. "She was taken much too soon."

Kootenai County sheriff's spokesman Stu Miller told reporters the incident in the store about 40 miles north-east of Spokane, Washington, was an accident. Mrs Rutledge's husband was not in the store when the shooting happened at about 10.20am, but he arrived shortly afterwards. All the children were taken to a relative's house.

Mrs Rutledge, from Blackfoot, Idaho, about 380 miles from Hayden, was visiting for the holiday season. Police said she was browsing the store's electronics section when the incident occurred, according to broadcaster KREM 2.

The Sheriff's office said in a statement: "Detectives are currently processing the scene."

Staff and shoppers in the store were evacuated. The shop remained closed while police carried out their investigation. Hayden has a population of around 10,000.

Lt Miller tweeted that the store would not re-open until 6am on Wednesday.

A Walmart spokeswoman, Brooke Buchanan, said in a statement: "A very sad incident occurred at our store today in Hayden involving the death of a female customer. We are working with the Kootenai Sheriff's department as they investigate what happened."

The shooting was immediately seized upon by campaigners and social media observers as an example of why gun laws in the US need changing.

Earlier this year, politicians in Idaho passed legislation to allow concealed weapons on the state's public college and university campuses. Despite facing opposition from all eight of the state's university college presidents, the politicians sided with gun rights advocates who said the law would better uphold the Second Amendment.

Hayden resident Dwight Van Horn, who sits on the board of the National Rifle Association, said the NRA would not be issuing a statement on the shooting at this time.

"We prefer to give people some time and let all the facts come in before we weigh in on anything like this," he told the Coeur d'Alene Press.

The shooting came as an internal police investigation confirmed that a man shot dead by a police officer in a petrol station forecourt in suburban St Louis last week had pointed a gun at the officer. Berkeley Police Chief Frank McCall said several witnesses had told police Antonio Martin pointed the weapon at the unidentified officer.

The police officer was responding to a report of shoplifting on December 23 and Mr McCall said Mr Martin matched the description of the suspect.

His shooting followed the killing of 18-year-old Michael Brown by a police officer in neighbouring Ferguson on August 9. The shooting provoked renewed public demonstrations and on Monday several dozen people gathered again at the convenience store before setting off on a protest march.