Thirteen hours before Daphne Caruana Galizia was killed in a car bomb explosion, a suspicious device was switched on in Bidnija and remained active until it received a text message at the time of her death. 

Information about the October 16 bombing was relayed to magistrate Claire Stafrace Zammit in court on Tuesday afternoon, as the compilation of evidence against three men accused of killing Ms Caruana Galizia finally got underway.

Inspector Keith Arnaud told the magistrate of the suspicious SIM cards identified by investigators; of odd debris, including a piece of plastic with the word "card" printed on it, discovered at the crime scene; and revealed that one of the murder suspects' phones was already being tapped at the time of the murder.   

The court hearing got off to a bumpy start in the morning, when defence lawyers asked the magistrate to recuse herself as well as to refer the case to a Constitutional court, saying there were grounds to believe the chief justice had been unduly pressured when assigning a magistrate to the case. 

BLOG: A blow-by-blow account of the court session

Magistate Stafrace Zammit disagreed, first dismissing the recusal request and then, after a three-hour deliberation period, also ruling that the defence's plea to have the case referred to a higher court was frivolous. 

Inspector Arnaud, who is leading the murder investigation, was the first witness to take the stand. 

In a one-hour testimony which will be resumed on Wednesday morning, the inspector touched on mobile phone data gathered by police, a "fresh-looking" cigarette butt discovered at a vantage point by tat-Tarġa Battery and Grand Harbour CCTV footage which showed one of the accused's boats leaving the port on the morning of the murder. 

George Degiorgio (Iċ-Ċiniz), his brother Alfred (Il-Fulu) and Vince Muscat (Il-Koħħu) all stand accused of having murdered Ms Caruana Galizia, arguably Malta's most renowned journalist, on October 16.

Phone tapping

Inspector Arnaud told the court that police were already tapping the phone of George iċ-Ċiniz at the time of the murder. 

Wiretaps showed how on the day of the murder, Mr Degiorgio called up two separate people asking them top up a Vodafone phone number with €5 in credit. 

That topped up device, the inspector told the court, had only made contact with two numbers previously, and was in the same  location as Mr Degiorgio at the time. 

With the help of a specialised FBI team, local investigators had identified two suspicious phone numbers, he told the court. One of those numbers lost contact with the tower at precisely the moment it received contact at 2.59pm, the inspector told the court. 

That time tallies with the moment the bomb that killed Ms Caruana Galizia went off. 

The SIM cards were used in 2G mobile phones, including a Nokia 105, but on one occasion the IMEI registered belonged to a circuit board most commonly used to remotely send commands. 

Both numbers had been activated in November 2016, but the first activity on them was registered in January. They swapped text messages at that point, and again exchanged SMS' in August. The third time they were used was on that fateful October afternoon. 

Out at sea

Inspector Arnaud told the court that investigators believed the message that set off the explosion was sent from out at sea, and explained that they reached that conclusion by examining cell tower data. 

When investigators discovered that the Degiorgio brothers both owned boats, they began to scour CCTV footage from the Grand Harbour to try and spot them. 

Sure enough, the inspector told the court, they noted one of the boats, the Maya, leaving the Grand Harbour at around 8am on the day of the murder and again outside Valletta at around 2.50pm. 

The compilation of evidence will continue on Wednesday morning at 10am.