Vincent Ryan, who was shot in Finglas, north Dublin on Monday afternoon, has died.
The victim is the brother of Real IRA crime boss Alan Ryan, who was murdered in 2012 as part of a gang feud.
Vincent Ryan was shot at around 3.15pm this afternoon.
It is understood that he had dropped his partner and a child to a house and was sitting in the driver's seat of a white Volkswagen Golf car when he was shot at by a gunman travelling in another car.
It is understood that Mr Ryan was alone in the car at the time of the shooting - and the woman and child were not in the car at the time.
A silver grey Volkswagen Golf with alloy wheels approached the car of the victim and fired a number of shots.
The vehicle then sped off in the direction of Clune Road in Finglas. It is not clear how many people were in that car.
The vehicle which is believed to have been used by the killers was found burned out in the Victoria Bridge area in Kildare.
Initial reports were that the 25-year-old was shot up to three times in the attack.
However, tonight, gardai said they didn't know how many shots were fired or what type of weapon was used.
Mr Ryan was well-known to gardai, and has a number of convictions for his dissident republican activities.
Today's shooting is believed to be linked to Alan Ryan's murder and an on-going feud with a north Dublin drug gang.
Gardai have sealed off the area where the attack took place and paramedics were earlier in attendance.
The injured man was brought to the Mater Hospital in "serious condition" - but died shortly after 9pm.
Members of the Armed Response Unit patrolled the Finglas area this afternoon, while gardai and detectives cordoned off a large portion of the road where the attack happened.
Garda forensic officers are continuing to examine the Volkswagen Golf that the victim was sitting in when he was targeted.
The passenger window of the vehicle was shattered but it is thought that the deceased was sitting in the driver's seat.
Cllr Paul McAuliffe came across the scene as he was driving home from the shop with his family.
The father-of-two lives nearby the scene of today's incident with his wife and two children.
"I live around the corner, I was on the way to the shops when we came across the scene," he told Independent.ie.
"The two kids were in the back of the car. At this stage the emergency services and some media were at the scene.
"This is another shooting in the heart of the community, normally I say 'the community' and now I'm saying 'my community', I live so close with my family," he continued.
"There has been an increase in gun crime across the whole city in the last couple of years.
"We need a dedicated unit to police the city. I don't care what colour or creed the next government is, they need to tackle this when it is now happening on an almost weekly basis."
The man who was shot today was also the victim of a brutal daylight attack in Dublin's north inner city a few months ago.
He was hospitalised after that attack. That incident occurred in front of a young woman who was with him at the time.
"He was cut from ear to ear in this brutal daylight attack. He is still in hospital," a source said at the time.
His injuries at the time were described as not life-threatening.
Local Fianna Fáil councillor David Costello said the people involved in today's shooting "have no consideration" for the public and are "running around the city like cowboys".
"This is terrible, for this to happen in a quiet residential area, you just wouldn't expect something like this to jump out at you," he told Independent.ie this afternoon.
"Whatever happens with the government over the next few days, they need to look at resources and tackle these thugs.
"These shootings are happening in residential areas and these people have no consideration for anybody else.
"The are running around the city like cowboys. They don't play a part in Irish society," he continued.
"We have to tackle this, I don't want my children growing up in a community where this is happening week in and week out.
"This happened in pure daylight. There were children coming home from school, parents pushing buggies home from creche.
"These people have no regard for human life."
Cllr Costello said he feels sympathy for the families involved but described the shootings as 'gang warfare'.
"These people are putting the rest of us at risk," he added.
There is no indication at present that this is connected to the murder of David Byrne in the Regency Hotel on February 5, or the murder of Eddie Hutch Snr in Ballybough on February 8.
They have appealed for people on McKee Road in Finglas, who may have witnessed the shooting, to contact them.