Paraic's investigations include the first TV report from inside the ranks of the English Defence League and an exposé of how the global online game Habbo Hotel was putting children at risk, resulting in a mass exodus of investors.
He was the first TV reporter on the ground in Brixton and Croydon as the riots broke out in 2011.
Before joining Channel 4 News he worked at the BBC as an investigations reporter for BBC London News and Newsnight on occasion.
Prior to that he was a community worker in Ireland and south London.
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What drove the university-educated Londoner Ibrahim al-Mazwagi to fight and die in Syria's civil war? What drove him to jihad and how many others are there like him in the UK?
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Far-right Hungarian party Jobbik is one of the country's most successful political parties. It is anti-Semitic, anti-EU and anti-Roma and is described by some as the incarnation of the new Europe.
A British blogger has been monitoring weapons used in the Syrian conflict, providing important analysis of the conflict for human rights groups - while working from his Leicester home.
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New footage emerges of the bloody aftermath of the hostage taking at an Algerian natural gas facility, in which nearly 40 hostages were killed. Paraic O'Brien reports.
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The tabloids are dominated by headlines about Prince Harry killing the Taliban. But what did he actually say? And what about the "not necessarily politically correct" posters in Camp Bastion?
As he returns from duty in Afghanistan, Prince Harry offers a rare insight into juggling his roles as a prince and pilot - revealing that he does not always get the balance right.
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Channel 4 News learns that the death of a British schoolgirl in Jamaica could have been connected to a lottery scam. Imani Green, from south London, was killed in the town of Duncans on Friday.
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Today's report into Jimmy Savile's career of abuse, which lasted for 54 years, details allegations as recent as 2009 and includes one incident in which a dying child was touched inappropriately.
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Amid claims, denials, legal threats and apologies, one fact remains: we still do not know the truth about children abused in north Wales. Paraic O'Brien anticipates where the two reviews will lead.
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From the initial investigation into north Wales child abuse in 1991 to the Waterhouse inquiry in 2000, Sian Griffiths has collated details of every allegation and document surrounding the scandal.
Exclusive: Steve Messham tells Channel 4 News he passed photographs of children being abused, including himself, to the police but they failed to act.
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Channel 4 News reporter Paraic O'Brien looks at Jimmy Savile's time as head of a taskforce at psychiatric hospital Broadmoor.
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The former headmistress at Duncroft approved school, where the Jimmy Savile scandal started, is claimed to have said the police never contacted her in connection with abuse at the institution.
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Channel 4 News has obtained an email involving the Newsnight team that worked on the abandoned Savile expose. Paraic O'Brien reports.
Exclusive: An email sent by a reporter on Newsnight's axed Jimmy Savile investigation suggests editor Peter Rippon played down the story because "it was 40 years ago... the girls were not too young".
The BBC says Newsnight Editor Peter Rippon will "step aside with immediate effect" pending an investigation into the decision to drop the programme's report into allegations against DJ Jimmy Savile.
Why did so many individuals and institutions ignore the warnings about Jimmy Savile? Was it the tyranny of celebrity? Or an outdated, male-dominated culture that was happy to turn a blind eye?
As the BBC's director-general apologises, Jimmy Savile's former producer tells Channel 4 News nobody from the corporation has contacted him, despite the fact he worked for the star for 21 years.
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The British entrepreneur and inventor Simon Woodroofe has re-engineered a city centre studio apartment into flexible suite by using some mechanical tricks from the stage.
BMW launches an investigation into its vehicles' security after discovering a high-tech security loophole which has seen top-of-the-range cars driven away without the owners' keys.
