The scene in London after last week’s terror attack. Photo: YouTube

Before he drove violently into the crowd on Westminster Bridge, and before plunging his knives into a police officer’s body, Khalid Masood‘s twisted path to terrorism followed an all too familiar pattern — from petty crimes, to prison radicalization, to violent jihadist.

Last week, radical Islamist terrorism once again struck innocent victims in Europe, killing four people in London and injuring at least 50 more.

Terrorist organizations like ISIS constantly recommend the instruments of cruelty that were used in this attack: a motor vehicle and a knife. Similar weapons have been used in the past to kill non-believers in Berlin, Nice, Woolwich, Jerusalem, Quebec, Oklahoma City and beyond.

The emerging profile of the London terrorist also paints a familiar image of a jihadist bent on killing as many people as possible on the path to paradise.

Mr. Masood, a 52-year-old UK native, was born on Christmas day in Kent. His given name was Adrian Elms, and he was raised as a Christian. He was known as an intelligent student, and a promising athlete during his time at the Huntley School for Boys. He spiraled downward from there, starting with a 1983 arrest for property damage. He spent time in three different correctional facilities, including for assault.

It was in prison that he is believed to have been radicalized.

The susceptibility of British inmates to Islamist radicalization is well documented. Extremist literature, like ISIS’s Inspire magazine, is present at UK jails, and so are convicted terrorists who try to solicit new recruits.

The vast majority of imprisoned terrorists refuse to attend any de-radicalization programs, which led former Scotland Yard Counter Terrorism Commander Richard Walton to tell Sky News that “very few” inmates convicted of ISIS-related crimes had been reformed. Other critics go even further, noting “that many ‘deradicalization’ programs established by Western governments have been fraught with repeated and embarrassing failures.”

Hanif Qadir, a former jihadist, believes that prison chaplains are unable to address the problem — because many of them may sympathize with a form of Islam that is radical in nature. This problem, unvetted Islamic clergy, was also found to exist in the US prison system, according to a Department of Justice Inspector General report in 2004.

US government records show that thousands of articles by Islamist ideologues like Hasan al Banna — the founder of the Muslim Brotherhood — and others such as Syed Qutb and Anwar al-Awlaki are available in US prison libraries.

My book, The Fertile Soil of Jihad, documents how ex-cons have often followed up their prison radicalization with travel to Islamist hotspots in the Middle East for further indoctrination. Masood went down that road as well.

He traveled to Saudi Arabia and worked there for several years after his release from prison. When he returned to the UK, he settled in Luton, a city well known for radical Islamist elements, including the radical Islamic cleric Anjem Choudary, who is now serving time in prison for terrorism-related crimes. Sometime after returning to the UK, Masood became a person of interest in an ongoing terrorism investigation, although MI-5 never connected him directly to any specific terror plot. He simply fell off the radar until last week’s attack in London.

An alarming number of recent terror plots and attacks involve people who started out as criminals, were radicalized in prison and then re-entered society bent on killing in the name of Allah. The 2010 New York State Police Vigilance Report found that almost 50 percent of people charged with terrorist-related crimes had prior contact with the criminal justice system. The recent Paris and Brussels terror attacks were in part carried out by former inmates, and attacks in Berlin, Copenhagen and Toulouse were also committed by individuals radicalized in prison.

Islamist radicalization in the prison system is a global problem that must be recognized and addressed effectively. Yet some groups, like the Anti-Defamation League, choose to focus more on the threat posed by white supremacist prison gangs and appear to overlook the threat posed by radicalized Islamist ex-cons, some of whom have specifically targeted the Jewish population for attacks.

Examples include the Newburgh Four plot to bomb a New York synagogue, Mohammed Merah’s shooting attack on a Jewish school in Toulouse, France, and Amedy Coulibaly’s massacre inside a Paris kosher grocery store.

Kevin Smith, the former Assistant US Attorney who successfully prosecuted a group of inmates who formed a terrorism cell within the California Department of Corrections known as Jam’iyyat Ul-Islam Is-Saheeh (JIS), testified before the House Committee for Homeland Security that: “It is my professional opinion that this particular group of radicalized inmates presents an exponentially greater danger to innocent individuals and civilians out on the outside.”

Counter terrorism authorities have an opportunity to act decisively against this group of potential terrorist recruits before the next attack occurs. Prison is a controlled environment. Radical literature must be removed. Clergymen must be better vetted. And inmate associations and communications must be better monitored. Prison officials do not need a FISA warrant to listen to an inmate’s telephone call, or to read his mail.

Monitoring terrorists who are about to be released from prison must be enhanced to include a registry, much like that required for sex offenders. And information regarding radicalized inmates must be shared between correctional, law enforcement and intelligence agencies. The present system of cooperation is sporadic and often subject to turf wars.

Without these tools, we will once again be forced to watch the familiar story of the common criminal turned violent terrorist who murders innocent men, women and children.

IPT Senior Fellow Patrick Dunleavy is the former Deputy Inspector General for New York State Department of Corrections and author of The Fertile Soil of Jihad. He currently teaches a class on terrorism for the United States Military Special Operations School.