LYRA McKee's killer has been identified as a short and stocky man in his late-teens by police who have released an image of their chief suspect.
As police investigating the murder released new footage yesterday, detective Superintendent Jason Murphy appealed for help from the people of Derry's Creggan estate to "get me through the door of a courtroom".
Police have been able to pinpoint the movements of the gunman and two associates one minute before the writer and activist was shot in the head during rioting in Derry shortly before midnight on Thursday April 18.
He is seen walking with a taller man masked man from Creggan shops on Central Drive towards the crossroads at the epicentre of the rioting. Both are following another taller man who is carrying what appears to be a box of petrol bombs.
Mr Murphy highlighted the "shorter (man)... of stocky build".
"It is of my belief that he is the gunman that fired indiscriminately into the crowd and placed the community and police officers at risk," he said.
"I believe he is the person who took the life of Lyra McKee."
He added that the gunman will carry a "very heavy conscience" over Ms McKee's murder.
Mr Murphy said, despite suggestions of children as young as 10 being at the forefront of the trouble, he believes all those in the area at the time were in their "late teens" - including the gunman.
The murky night-time image does not give a clear idea of the colour of the clothes the killer or his associates were wearing.
However, a later well-lit shot of the tall man with a camouflage-patterned mask, who was and walking ahead of the pair, reveals he was wearing blue skinny jeans, blue Nike trainers with a white tick and a white sole.
In separate footage he can be seen holding a petrol bomb which is being lit by another man wearing distinctive TEAM9 tracksuit bottoms.
Footage released earlier by the PSNI showed the man in the tracksuit bottoms apparently acting as a look-out for the dissident group.
More than 140 people have provided images, footage and other information to murder squad detectives, but Mr Murphy urged the community not to be scared to identify the main suspect.
"I believe that people in the community know who this individual is. I recognise that people living in Creggan may feel it is difficult to come forward to speak to police," he said.
"Today I want to provide a personal reassurance that we are able to deal with those issues sensitively."
He added that "messages of the potential for a better future" at Ms McKee's funeral "will be all in vain if we can't tackle the malign influences that some individuals continue to exert over our communities".
The police officer said information provided so far "simply gets me through the door but it doesn't get me to the door of a courtroom", stating his belief that the information is being withheld out of fear rather than an attempt to protect the murderer.
"I need people to contact my team to talk to us about what they know.
"Whilst the community information has been coming into us I have been keen to convert this information and intelligence into tangible evidence to allow us to bring this individual to justice.
"I need the public to tell me who he is.
"I do believe the community has information that can help us unlock the key to Lyra McKee's murder. I'm not sure individuals are protecting this person, but I believe they are frightened."
Forensic tests on the bullets fired have linked the gun to a calibre of weapon that was circulating on the nationalist estate and which has been used in previous paramilitary-style assaults there.
"It's symptomatic of the fact that weapons of this type are in circulation in Creggan and other areas of Northern Ireland and continue to bring misery every single day to these communities," Mr Murphy said.
