Melbourne, Australia — A man accused of killing 15 people at Sydney's Bondi Beach obtained firearms training in New South Wales state outside Sydney with his father, according to Australian police documents released on Monday.

The documents, made public following Naveed Akram's video court appearance from a Sydney hospital where he has been treated for an abdominal injury, said the two men recorded footage justifying the meticulously planned attack.

Officers wounded Akram at the scene of the Dec. 14 shooting and killed his father, 50-year-old Sajid Akram.

The state government confirmed Naveed Akram was transferred Monday from a hospital to a prison. Authorities identified neither facility.

The 24-year-old and his father began their attack by throwing four improvised explosive devices toward a crowd celebrating an annual Jewish event at Bondi Beach, but the devices failed to explode, the documents said.

Police described the devices as three aluminum pipe bombs and a tennis ball bomb containing an explosive, gunpowder and steel ball bearings. None detonated, but police described them as "viable" IEDs.

The pair had rented a room in the Sydney suburb of Campsie for three weeks before they left at 2:16 a.m. on the day of the attack. CCTV recorded them carrying what police allege were two shotguns, a rifle, five IEDs and two homemade ISIS flags wrapped in blankets.

Police also released images of the gunmen shooting from a footbridge, providing them with an elevated vantage point and the protection of waist-high concrete walls.

The largest IED was found after the gun battle near the footbridge in the trunk of the son's car, which had been left draped with the flags.

Authorities had been looking into a month-long trip by the father and son to the Philippines, where there's been a decades-long Islamist insurgency in the south of the country.

Australian Prime Minister Anthony Albanese said last week that the attack was inspired by ISIS, and there is an ISIS-affiliated militant group operating in a remote area of the Philippines.

But a receptionist at a hotel in Davao City told CBS News the attackers never left their room for more than a day. 

Authorities have charged Akram with 59 offenses, including 15 counts of murder, 40 counts of causing harm with intent to murder in relation to the wounded survivors and one count of committing a terrorist act.

The antisemitic attack at the start of the eight-day Hanukkah celebration was Australia's worst mass shooting since a lone gunman killed 35 people in Tasmania state in 1996.

The New South Wales government introduced draft laws to Parliament on Monday that Premier Chris Minns said would become the toughest in Australia.

The new restrictions would include making Australian citizenship a condition of qualifying for a firearms license. That would have excluded Sajid Akram, who was an Indian citizen with a permanent resident visa.

Sajid Akram also legally owned six rifles and shotguns. A new legal limit for recreational shooters would be a maximum of four guns.

Police said a video found on Naveed Akram's phone shows him with his father expressing "their political and religious views and appear to summarise their justification for the Bondi terrorist attack."

The men are seen in the video "condemning the acts of Zionists" while they also "adhere to a religiously motivated ideology linked to (ISIS)," police said.

Video shot in October shows them "firing shotguns and moving in a tactical manner" on grassland surrounded by trees, police said.

"There is evidence that the Accused and his father meticulously planned this terrorist attack for many months," police allege.

An impromptu memorial that grew near the Bondi Pavilion after the massacre, as thousands of mourners brought flowers and heartfelt cards, was removed Monday as the beachfront returned to more normal activity. The Sydney Jewish Museum will preserve part of the memorial.

Victims' funerals continued Monday with French national Dan Elkayam's service held in the nearby suburb of Woollahra, at the heart of Sydney's Jewish life. The 27-year-old moved from Paris to Sydney a year ago.

The health department said 12 people wounded in the attack remained in hospitals Monday.