A man has been arrested in connection with the murder of a 35-year-old in the latest gun killing in Dublin.
The victim, from St Teresa's Gardens in Dublin's south inner city, was dropped at St James' Hospital at about 7pm on Friday night by a man in a car after being shot. Warren was pronounced dead a short while after being dropped at the emergency unit. The killing is the 16th gun murder this year linked to criminal gangs and feuds.
A Mercedes C-180 with a 01-D registration believed to have been carrying the man after he was shot was found on Cork Street, less than a mile from the hospital. Further forensic examinations are to take place.
Warren's brother Paul was shot dead in 2004 aged 23 in a pub in Newmarket Square near the Liberties in revenge for the murder of Joseph Rattigan, brother of crime gang leader Brian Rattigan.
Warren was a known criminal involved in burglary and had low-level links to crime and drugs gangs, believed to be factions from the Crumlin and Drimnagh areas.
A feud involving gangs from those areas has run for years and claimed at least a dozen lives. His brother Paul was not regarded as a major player on the crime scene at the time of his death.
Gardai have repeated calls for anyone with information on the murder to come forward. In an official witness appeal, they said they particularly wanted to speak to anyone who may have seen a C180 blue Mercedes dropping Warren at the emergency department of St James' Hospital at around 7pm. They also called for anyone who may have witnessed suspicious activity around Cork Street, shortly after 7pm, where a blue Mercedes was found abandoned.
Individuals who may have seen or heard anything unusual around Great Western Way, the lane leading from Great Western Way to the Royal Canal Bank, Auburn Street and the junction of Great Western Way have also been urged to come forward.
Witnesses should contact officers at Mountjoy Garda station.