The police have given details in court of the investigation into the journalist Daphne Caruana Galizia’s murder. Ivan Martin maps out the key testimony and evidence – including crucial mobile phone data –  presented so far.

It started from the end: Police and FBI agents sifted through heaps of cell tower data to get to who they believe are the killers.

Data from the Bidnija area helped investigators identify a phone number that received an SMS at 2.58pm on October 16, exactly when the bomb went off, then vanished from the grid.

This was the first step in a long and complicated ‘data trawling’ investigation. Investigators believe that the number was linked to an electronic command board normally used in domestic appliances that can be activated remotely. This was the DIY detonator used in the car bomb.

Deeper analysis of the cell tower data shows that the SIM used in the bomb went active in the Bidnija area at around 2am on October 16 – which is when investigators believe the bomb was placed in Ms Caruana Galizia’s car.

The cigarette butt: A “small white car” frequented a rural area near the Tat-Tarġa Battery in the days leading up to Ms Caruana Galizia’s murder but then was never seen again. Witnesses who spoke to police investigators said that on the day of the murder, the white car was there again, but while they normally noticed a man inside, this time there was nobody.

Police found a collapsed wall next to where the car had been parked and followed a small path to a tree with a bird’s-eye view of Bidnija and of the road where the bomb went off. A “fresh-looking” cigarette butt was found at the vantage point – and forensic testing matched it to the DNA of the accused Alfred Degiorgio.

The spotter: Alfred Degiorgio is believed by inspectors to have been the spotter monitoring the Caruana Galizia household. Cell data has him in the Bidnija area the night before the murder and remaining at the vantage point until shortly after the 3pm explosion.

Investigators believe that Alfred called his brother George Degiorgio to inform him Ms Caruana Galizia had left the house and gave the go-ahead for him to pull the trigger.

But the first call was aborted after Ms Caruana Galizia returned to her house, having forgotten to bring her husband’s chequebook. The second call lasted 107 seconds, the exact time it took to drive from the house to where the bomb exploded.

The Maya, from which the bomb is believed to have been detonated.

The boat: Investigators believe George Degiorgio’s pleasure boat, the Maya, is central to the murder investigation. On the day of the murder, the boat, a Wellcraft Martinique 200, left its berth near the Marsa potato shed at around 8am.

The previous day Mr Degiorgio had told known associates of his that he was “going fishing”.

The vessel was seen turning north when it left the harbour and was tracked on a number of cell towers that face the sea. At the time the fatal SMS that detonated the bomb was sent, the Maya was spotted in the waters near the Great Siege Bell, where it stopped for a few minutes before heading back towards Marsa.

Shortly after the bomb exploded, wiretapped phone calls with George feature him boasting that he “caught two big fish today”.

The footage: Police officer Saviour Scerri told the court how on October 25, CCTV footage from Transport Malta’s Grand Harbour monitoring cameras was scoured.

The police were looking for footage of George Degiorgio’s Maya leaving the harbour on the day of the murder. Sure enough, there the boat was, leaving Valletta on that same morning.

Officer Scerri told the court how last month he had been sent to Valletta to film the same boat heading towards Marsa.  Stills of the footage have been submitted as evidence in the case.

The potato shed: The three men were all arrested in the Menqa area of Marsa on December 4 in one of the enclosures that form part of a former potato shed.

The shed, close to the Marsa Regatta Club, was raided by police and special tactical officers.

Alfred Degiorgio (il-Fulu), his brother George (iċ-Ċiniz) and Vince Muscat (il-Koħħu). They will stand trial for the murder.

The mobile phones: In the water just outside the shed where Mr Degiorgio’s Maya was berthed, scuba officers found several mobile phones, some identical to those used in the murder, others unrelated but belonging to the accused.

The top-up call: The Security Services intercepted a call from George Degiorgio’s phone while he was out at sea on October 16, asking an associate to top up his phone with €5 in Vodafone credit. After this person failed to help him, Mr Degiorgio called another friend to ask for help – telling him to be quick.

The top-up is one of the most incriminating pieces of evidence in the police investigation, as investigators believe it links George Degiorgio to the crime.  They testified that after detonating the bomb by SMS, Degiorgio messaged his wife with the words: “Buy me wine, my love.”

The phone signals: According to cell tower data, the phone used to send the fatal message was out at sea on the day of the murder.

Investigators speaking in court explained how the pattern of bouncing signals from cell towers pointing out to sea, which located the phone at Sliema and in the Xagħjra area, indicated a signal coming from the sea. A similar pattern was noted from Mr Degiorgio’s personal phone on the day.