LONDON, UK — In the deepening investigation of the Boston Marathon bombings, federal officials have reportedly found copies of the Al Qaeda magazine Inspire and other extremist materials on a computer belonging to Katherine Russell, the widow of suspect Tamerlan Tsarnaev.

If these reports are true, and if this case took place in the UK, no other evidence would be needed to arrest and prosecute Russell, 24.

Simply having a copy of Inspire — or any other materials deemed “likely to be useful to a person committing or preparing an act of terrorism” — is a crime here.

Under Section 58 of the UK’s Terrorism Act, a 2000 law granting sweeping powers to law enforcement, it is a criminal offense to download, copy or otherwise possess Inspire. Same goes for bomb-making instructions, extremist speeches, or any number of materials that in the United States are protected under the First Amendment.

No other evidence of terrorist activity, or intention to engage in it, is necessary to prosecute under the UK statute, which carries a sentence of up to 10 years in prison.

“You don’t have to necessarily be planning any terrorist activity to be prosecuted under that bit of legislation, if you are possessing those type of materials,” a Scotland Yard spokesman told GlobalPost on the condition of anonymity.

The law makes an exception for individuals who can demonstrate “reasonable excuse” for accessing the material, such as academics or investigators. It is a narrow exemption, however, and does not automatically cover journalists or others reading the materials for research or educational purposes.

“We wouldn’t say just because you were doing it for journalistic purposes you would be immune. You have to be careful,” the Scotland Yard spokesman said.

Launched in 2010, Inspire is an English-language online magazine published by Al Qaeda in the Arabian Peninsula. It has the earnest stock-art images and slightly off-kilter layouts of a doctor’s office newsletter. But it features articles like “Make a Bomb in the Kitchen of Your Mom” and “Open Source Jihad: Sending and Receiving Encrypted Messages.”

The magazine’s second issue carried an op-ed by US citizen Samir Khan, 24, in which he wrote that he was “proud to be a traitor to America." Khan, whom US government officials have named as the editor of Inspire, was killed by an American drone strike in Yemen in 2011, along with the radical cleric and Inspire backer Anwar al-Awlaki.

Copies of Inspire and other extremist texts, speeches and images have surfaced in the confiscated property of terror suspects in the United States and the United Kingdom. In the UK, however, merely possessing these items is a crime.

There are no firm figures on exactly how many people have been arrested and tried under the law since 2000. In most cases, Section 58 charges are bundled along with other terror or criminal offenses, said Simon McKay, a lawyer who has advised the UK government on terror cases.

Yet there have been several recent cases of people charged solely for possession of terror-related documents.

In April, a former Hackney council employee named Khalid Javed Baqa, 48, was jailed for two years after being found with several hundred copies of CDs containing “extreme ideology and material relating to violent jihad,” according to the Metropolitan Police.

Niall Ferguson, 21, received a suspended 18-month jail sentence in February under Section 58 after he was found with copies of the weapon-making manual “The Anarchist’s Cookbook,” a jihadi training manual and instructions for making the poison ricin. Judge Adrian Fulford said he was satisfied that the “young and naive computer addict” was not a terrorist.

And in December, a 22-year-old accountant named Ruksana Begum received a 12-month sentence after police searching her home discovered a memory stick containing two editions of Inspire in her purse. Begum’s brothers were convicted in a 2010 plot to blow up the London Stock Exchange. Her husband was also arrested in 2012 and charged with traveling to Pakistan to obtain terrorist training.

Begum pleaded guilty to the possession charge. She told the judge that she accessed the magazine to understand what had drawn her brothers to extremism, an explanation the judge accepted.

“There is no evidence that she was motivated by their ideology or was preparing to follow them,” said Justice Fulford at her sentencing, adding that Begum was “of good behavior and a good Muslim.”

The UK approach to such documents is radically different from the US approach.

“In the United States, not only is possession of Inspire magazine constitutionally protected, but writing something like Inspire magazine is constitutionally protected,” said Ben Wizner, director of the Speech, Privacy and Technology Project at the American Civil Liberties Union.

If such material isn’t found to be a direct incitement to violence, and the owner isn’t coordinating with a terrorist organization, then it’s protected under the US Constitution’s First Amendment. The UK approach “invests so much authority in the government,” Wizner said.

“We’re always very skeptical of government line-drawing, because it’s never enforced in the way that people would like it to be,” Wizner said.

The UK is seeking to further its powers of internet surveillance. A draft Communications Data Bill — known in the media here as the “snooper’s charter” — would allow the government to track all email, internet and text use in the country.

The bill died in Parliament last year, though mentions of internet security in the Queen’s Speech on Wednesday indicate that the government may revisit the issue in this legislative session.