US flag flies alongside a sign in honor of the four Marines killed in Chattanooga, Tennessee on Thursday. Photograph: Reuters

The suspect in the fatal shootings of four US Marines traveled to Jordan and possibly other Middle Eastern countries for seven months last year, autho(...)

Military veteran David Croft brings flowers to a memorial near where the shooting in Chattanooga, Tennessee took place. Photograph: EPA.

Investigators on Friday sought to determine what led a 24-year-old gunman to open fire at two military offices in Chattanooga, Tennessee, killing four(...)

Gary Davis, of Johnstown Court, Kilpedder, Co Wicklow,  pictured at the Four Courts for a High Court action. Photograph: Courts Collins

The United States is seeking the extradition of an Irishman whom it claims was an administrator of the Silk Road website which offered anonymity to(...)

On duty: Lewis Merletti, between Hillary and Bill Clinton, during a ceremony to make the US president an honorary freeman of Dublin in 1995

Sleepy Dungarvan, on the Waterford coast, might seem an unusual location for a gathering of spooks and cops, but every two years it hosts a conference(...)

Office of Personnel Management in Washington: data on millions of US government workers has been hacked. Photograph: Shawn Thew/EPA

Rarely has a computer hack of personal information, allegedly by agents of a foreign government, caused such a stir in Washington DC. A breach at the (...)

Yemeni al-Qaeda chief Nasser al-Wuhayshi speaks at an unknown location in this still image taken from video obtained by Reuters TV. Al-Qaeda in Yemen said its leader,  al-Wuhayshi, was killed in a US bombing, in major blow by the United States against the global militant group’s strongest branch. Photograph: Reuters TV

The deputy leader of al-Qaeda, Nasser al-Wuhayshi, has been killed in a US bombing in Yemen, the group said on Tuesday, removing the director of a str(...)

There are concerns markets are increasingly being moved by computer algorithms rather than by any fundamental catalyst, resulting in increased volatility and potentially causing instability or even crashes. Photograph: Getty Images/iStockphoto There are concerns markets are increasingly being moved by computer algorithms rather than by any fundamental catalyst, resulting in increased volatility and potentially causing instability or even crashes. Photograph: Getty Images/iStockphoto

The growth of computerised trading has brought obvious benefits to investors. Trading costs have been slashed; complex information is quickly processe(...)

FBI crime scene investigators document evidence outside the Curtis Culwell Center. Two men opened fire with assault weapons on police Sunday night who were guarding a contest for Muslim Prophet Muhammed cartoons. A police officer returned fire killing both men. Photograph: Brandon Wade/AP

Federal agents for years monitored one of the two gunmen who were shot dead after opening fire with assault rifles at a heavily guarded Texas exhibit (...)

The US authorities claim the Silk Road website, shut down by the Federal Bureau of Investigation (FBI) in 2013, was an underground website that hosted a “sprawling black market bazaar” on the internet, where items including drugs, firearms and counterfeit money were bought and sold.

An applicaton for the extradition of a Co Wicklow man to face trial in the United States on conspiracy charges arising from his alleged links to a nar(...)

Heather Mack (19) and Tommy Schaefer (21) have been sentenced over the murder of Mack’s mother in Indonesia. Photograph: Getty Images

An Indonesian court found a young US couple guilty on Tuesday of murdering the woman’s mother and stuffing her battered body into a suitcase on the re(...)