On 17 October 2023, an explosion tore through the courtyard of al-Ahli Hospital in Gaza City. Hundreds died. Forensic Architecture (FA), the research centre based at Goldsmiths, University of London, responded with a digital reconstruction of the blast, tracing lines from the crater to shrapnel markings on surrounding buildings to establish how the incident unfolded. The work features in FA's 2024 project When it Stopped Being a War: The Situated Testimony of Dr Ghassan Abu-Sittah.

The episode shows FA's method in miniature. When an Israeli military spokesperson appeared on the BBC and CNN holding up a still of a flash in the sky, attributing the explosion to a misfiring rocket launched by Palestinian Islamic Jihad, FA geolocated, stabilised and positioned the original footage — alongside another video of the same event — within its existing 3D model of Gaza. The explosion pictured, FA showed, was in fact an Israeli interceptor.

Everything turns on the detail. As Piyel Haldar writes, detailism is a technique of visual dissociation: stepping back from what is clearly visible to attend to what seems irrelevant. Art historian Giovanni Morelli used it to identify fake paintings by the tiniest features; Freud acknowledged its similarity to psychoanalysis. FA amplifies the method's potency by analysing and measuring many photographs of an event at once.

The lineage is long. Nadar photographed Paris from a tethered hot-air balloon in 1858; two years later JW Black flew above Boston Common for Boston, as the Eagle and the Wild Goose See it. Photogrammetry was used for topographic surveying as early as 1851 by French military officer Aimé Laussedat, and in 1868 government surveyor Albrecht Meydenbauer created the first 360-degree photographic record of Berlin. In his 1936 essay From Pigment to Light, László Moholy-Nagy called the meeting of photography and cartography an "advance in technique [that] almost amounts to a psychological transformation of our eyesight". Allan Sekula named airplanes and photography "these two globalising mediums" — a union that helped rationalise warfare.

FA founder Eyal Weizman has spent decades investigating the violence enacted upon Palestinians by the State of Israel, the land of his birth. He has mapped the militarisation of airspace, politicised access to water, and the patchwork of roads, checkpoints and borders that produce what he calls a hollow land. "The 'politics of verticality' entails the re-visioning of existing cartographic techniques," Weizman says. "It requires an MC Escher-like representation of space, a territorial hologram in which political acts of manipulation and multiplication of the territory transform a two-dimensional surface into a three-dimensional volume."

The philosophical footing came from Edward Said, whose insistence on counter-cartography as an act of resistance underpins the practice of counter-forensics — the use of mapping, geolocation, photogrammetry, open-source data and 3D modelling software to investigate state violence.

FA's investigation into the killing of Mark Duggan, shot dead by an anonymised Metropolitan Police officer in Tottenham on 4 August 2011, shows the method at domestic scale. The inquest had returned a verdict of lawful killing. FA built a 3D model from photographs made public by the inquest and from site surveys, layering police statements to expose contradictions between their accounts. Biomechanics experts told FA that the gun allegedly thrown by Duggan — found almost seven metres from where he was shot — would have had to travel at 6.7 metres per second, at an angle of 31–40 degrees. An independent pathologist deemed it "very unlikely" Duggan could have thrown it that distance after being shot. FA also noted that of the seven video files comprising the 'Witness B footage', only six were referred to by a specialist image analyst employed by the inquest — and that a gap in the footage at a heavily scrutinised moment went unmentioned.

That gap echoes the withheld Frame 313 of Abraham Zapruder's footage of the Kennedy assassination in 1963, which Life magazine, honouring Zapruder's request, kept unseen for 12 years. Film-maker Errol Morris calls the frame 'the forensic heart' of the 26-second film.

Uncertainty itself drives FA's investigations. Its written reports acknowledge it, though the authoritative narrators and clinically clear imagery of its finished presentations sit in tension with the concept of accepting the shadow of a doubt. FA's work circulates across museums, galleries and courts of law — spaces that afford different readings of the same material. The Killing of Mark Duggan appeared in the exhibition War Inna Babylon: The Community's Struggle for Truth and Rights at the ICA in London in 2021. Though the legal appeal predating FA's research failed, every element of the ICA show felt like a step towards justice, exposing the porous border between fact and proof.

FA's recent work on the German colonial genocide in Namibia shifts the reading of images from the art historical to the juridical. Researcher-in-charge Agata Nguyen Chuong describes how historical photographs and maps revealed the violence of the colonial archive. "Landscape photography, framing a Lebensraum for German settlers – and often disseminated as postcards – or cartographic annotations on maps, betrayed genocidal intentions of erasure and land dispossession before they materialised on the ground," she says. "In this context, the notion of 'photographic restitution' – returning images to their environmental and cultural contexts – became central to our method."

Comparing contemporary and archival images of Namibia, FA traced changes in grass growth that, combined with details of land degradation, evidence a crime we might soon name as ecocide. An 1897 map shows how proposed native reserves would contain Indigenous people and restrict their movement. Testimony from the elders of Otjimbingwe, read against the contours of historical maps, proved that what colonial logic dismissed as barren void was in fact a richly biodiverse, fertile landscape. "Inherited testimonies add resolution to the subtle visual cues in the photographs, transforming our reconstructed landscape into a lived environment," Nguyen Chuong says. "Through these methods we attempted to re-situate this fraught material within the ontologies colonial violence had sought to erase."

Testimony here expands the possibility of the image, repositioning the narrator from someone to whom something terrible happened into the source of vital knowledge. FA developed its process for engaging traumatised memory with Goldsmiths' Forensic Psychology department to avoid retraumatisation.

The individual practitioner has not disappeared. Former Royal Marine Giles Price, who worked on operations in northern Iraq in 1991 at the age of 17 and suffered medical discharge after exposure to chemical weapons, followed by 14 years of major surgeries, was commissioned by The New York Times Magazine in 2017 to document wrongly-targeted coalition strikes in Mosul — strikes misreported in the US and UK press as the most accurate air campaign in history.

Price knew he required the aerial view. "I wanted to mirror the surveilling and targeting point of view, but with the hi-res and clarity to see the destruction caused by it," he says. "At ground level, the rubble was comprised of homes and schools." Unable to take a drone into Iraq, he mounted his camera on a 12-metre telescope carbon fibre pole, triggered with a wi-fi remote. Later, blocked by geolocation restrictions on a drone rented from an Iraqi army officer, he found a workaround in photogrammetry apps.

His series Phantom Pro grew out of a relationship with Iraqi videographer Ayar Rasool, whom Price trained over WhatsApp to fly photogrammetry apps. Price paid Rasool to make a photogrammetry set of the al-Nuri mosque, site of Abu Bakr al-Baghdadi's 2014 caliphate sermon, which Isis blew up before Mosul fell. Amnesty International reported as many as 10,000 civilians killed in the nine-month battle for the city, calling on the Iraqi state and US coalition forces to accept responsibility. In Price's images, data points cluster like tiny green targets; Azersjkhan Neighbourhood uses what he calls "the expressive tactic of leaving visible the computational processes and photogrammetry software artefacts". By inserting these constructed images back into Google Earth, Price reshapes both corporate and state narratives of what is available to be seen.

The context sharpens the stakes: international press remain banned from entering Gaza, and nearly 200 local — mostly Palestinian — journalists have been killed by the Israeli military since October 2023. It is frequently medics and citizens who are today's documentarians. As Harun Farocki noted in his 1989 film Images of the World and the Inscription of War, we have more pictures than the eyes of the world are capable of evaluating. FA and Price suggest a photography that no longer merely represents but explains, clarifies and sometimes proves — and, as the source puts it, mapping techniques can also simply help us to know that there is a way home.

Giles Price's series Phantom Pro is on show as part of Impact Kyiv: Forum of War and Conflict Photography at The Ukrainian House of Photography from 15–18 October 2026.