Audio analysis of footage of an Israeli attack on an aid worker convoy last month suggests that some of the shots were fired from as little as 12 metres away.
The Israel Defence Forces (IDF) has admitted killing the unarmed medics, saying that the convoy was acting “suspiciously”.
A spokesman told journalists in a 5 April briefing that an initial investigation had found there was “no firing from close distance” during the incident on 23 March.
Sky News has spoken to two independent audio forensic experts who analysed a 19-minute video of the attack filmed by Rifaat Radwan, one of the medics who was killed.
The expert analysis shared with Sky News suggests that the first gunshots heard in the video are likely 40-50 metres away from the phone recording the footage, but gunshots heard later are closer in distance – around 12-18 metres away.
In response to our findings, the IDF said a preliminary inquiry indicated that troops “opened fire due to a perceived threat following an encounter in the area”.
The shooting continues for six and a half minutes
The 19-minute video shows a convoy of marked ambulances and a fire engine travelling south along a road east of Rafah city.
A spokesman for the Israeli military initially claimed the emergency vehicles were travelling without any headlights or emergency signals, but the IDF later backtracked after the video disproved this claim. All vehicles visible in the convoy have their emergency lights on.
The video below shows the first gunshots fired during the attack.
After analysing the video, two audio forensic analysts told Sky News that “multiple shooters” were likely involved in the incident and “over 100 gunshots” were fired.
Audible gunshots are first heard 13 minutes and 35 seconds into the video, shortly after the convoy arrives at the scene of an earlier attack. The shooting continues for six and a half minutes.
Professor Rob Maher from Montana State University, an audio forensics expert working as an independent consultant, said: “The first few audible gunshots are likely 40-50 metres away from the (phone) microphone, based upon the crack-pop acoustic sequence and an assumption about the bullet speed.
“With so many audible gunshots, it seems likely that there were many firearms involved, and that those shooters were at different locations at different times during the many minutes of shooting.”
Most bullets travel faster than the speed of sound, this is called ‘supersonic’.
When a supersonic bullet is fired, the first sound you hear is the sharp ‘crack’ made by the bullet’s shockwave. After that, you hear the ‘bang’ from the gun firing, or muzzle blast. This second sound travels more slowly – at the speed of sound.
The time between the ‘crack’ and the ‘bang’ tells you how far away the gun is from the microphone. If the gun is far away, there’s a bigger gap between the two sounds. If it’s close, the gap is much shorter.
Another expert, Steven Beck of Beck Audio Forensics, estimated the distance of the first few gunshots to “around 40 metres”.
He added that the first audible shots are “most likely military rifles or carbines firing supersonic bullets that pass close to the recorder – meaning they are being fired at”.
Both forensic audio experts told us that as the video continues, the gunshots appear much closer – at a distance ranging between 12 and 18 metres. They explain that the “crack-bang” timing reduces in comparison to the start of the gunfire – indicating that the distance shortens.
Mr Beck said at the end of the video “there are more shockwaves followed by muzzle blasts. The shooter(s) at these times is much closer, with distances of 12m – 18m”.
Due to the overlapping gunshots heard in the video, from the audio it is not currently possible to rule out whether gunshots were fired back.
Prior to the attack, the ambulance from which the video is filmed had been searching for a group of paramedics who reported that they had been attacked by Israeli troops.
The ambulance travelled from southern Rafah up to the coast, before performing a U-turn and joining a convoy of other emergency vehicles.
The shooting began as the convoy arrived at the scene of the scene of the first attack.
In a statement to Sky News, the IDF said it is “conducting an inquiry into the incident, which took place in a combat zone, to uncover the truth.
“All the claims raised regarding the incident will be examined and presented in a detailed and thorough manner for a decision on how to handle the event.”
The IDF also says that six of the individuals killed were later identified as “Hamas terrorists”, though no evidence has been provided to support this claim.
The Data and Forensics team is a multi-skilled unit dedicated to providing transparent journalism from Sky News. We gather, analyse and visualise data to tell data-driven stories. We combine traditional reporting skills with advanced analysis of satellite images, social media and other open-source information. Through multimedia storytelling we aim to better explain the world while also showing how our journalism is done.