Self-confessed Daphne Caruana Galizia killer Vincent Muscat will testify against brothers George and Alfred Degiorgio, who, until last week, were his co-accused in the murder.

Muscat, known by his nickname il-Koħħu, reversed his previous not guilty plea to murder charges last week, registering an admission in a dramatic court hearing. He was sentenced to a 15-year jail term for his involvement in the 2017 assassination of the journalist.

That admission was described as a “significant, if not crucial development,” in an application filed on Monday by deputy attorney general Philip Galea Farrugia, in which he asked Judge Edwina Grima to authorise Muscat’s testimony in ongoing proceedings against the other two alleged hitmen and have him accepted as a competent witness in terms of law.  

Muscat will testify in the compilation of evidence against the Degiorgio brothers, with his name added to a list of witnesses in the case, after judge Grima upheld the request. 

In her decree, the judge ordered Muscat’s testimony to be heard during the current time-window during which the case is to resume before Magistrate Claire Stafrace Zammit.

Muscat’s admission and sentencing proved to be a momentous turning point in the ongoing investigations into the murder, resulting in the immediate arrest of the suspected bomb suppliers, Ta’ Maksar brother Robert Agius and Jamie Vella. 

Agius and Vella are pleading not guilty to complicity in the murder, following their late-night arraignment. 

Information supplied by Muscat about the 2015 murder of lawyer Carmel Chircop also led to the arraignment of the other Ta’ Maksar brother, Adrian, who was charged with commissioning the crime. 

Associates Jamie Vella and George Degiorgio were also charged with executing the fatal shooting on that October 8, 2015 morning at a garage complex in Bkara. 

All pleaded not guilty and were remanded in custody. 

Muscat has been granted a presidential pardon in exchange for testimony in the case concerning Chircop’s murder.