The Islamic State killer is identified as a young Londoner. (AFP/Getty Images via YouTube)

Mohammed Emwazi, the Kuwaiti-born Briton who has been identified as the Islamic State fighter "Jihadi John" notorious for beheading westerners, was a familiar face to British authorities during his time in London.

As my colleagues Adam Goldman and Souad Mekhennet reported, friends believe Emwazi started being radicalized after a planned trip to Tanzania, following his graduation from the University of Westminster. When Emwazi landed in Dar es Salaam with his two friends in May 2009, they were detained by police overnight and eventually deported.

Emwazi flew to Amsterdam, where he claimed that an officer from MI5, Britain’s domestic security agency, accused him of trying to reach Somalia. He was eventually allowed to return to Britain.

Emwazi moved to Kuwait in the fall of 2009, where he worked for a software development company. In late May 2010, Emwazi traveled to London for an eight-day holiday to see his family. When he arrived at Heathrow, he was questioned about what he was doing in Kuwait. He ended up returning to Kuwait instead of seeing his family, who told him in a phone conversation that British authorities had visited them.

A month later, Emwazi flew back to London again, except this time, he was detained and questioned for six hours at Heathrow, as British authorities fingerprinted him and searched his belongings. 

He tried to fly back to Kuwait the next day, but was prevented from doing so. It was then that Emwazi filed complaints regarding his treatment to the police. A few weeks later, on July 22, 2010, he met with London Metropolitan Police officers to discuss his treatment and follow up on his complaints.

The following letter was sent by the London Metropolitan police on Nov. 23, 2010, in response to Emwazi's complaints.

Emwazi received a letter from British authorities in November 2010. (Obtained by The Washington Post)
Emwazi received a letter from British authorities. (Obtained by The Washington Post)

Here is what the text of the letter said:

Dear Mr. Emwazi,

I am glad to report that we have now done everything you asked us to do in connection with the complaint you made at DPS Customer Service Team on 7th June 2010.

My colleagues and I have taken the steps that you discussed when you met with my colleagues on 22nd July 2010, and your concerns have been discussed with the officers in question.

I hope you are satisfied with the steps I have taken. You have the right of appeal to the Independent Police Complaints Commission (IPCC) if you think I have failed to follow the correct procedures. You have 28 days within which to make your appeal to the IPCC. You are advised to post your appeal in good time to ensure it reaches the IPCC before the end of the 28th day. The 28th day is 24th December 2010. Appeals received after 28 days may not be allowed unless there are exceptional circumstances.

You might want to consider using guaranteed next-day delivery post service to ensure that your appeal is received within time. If you do decide to appeal, this is the address to write to:

The Independent Police Complaints Commission

90 High Holborn

London WC1V 6BH

You can have a copy of the police record of your complaint, showing that your concerns have been formally recorded. If you would like this, you need to put your request in writing and send it to me within 3 months of the date on this letter.

Your sincerely,

Sharon Heaven

It is unclear whether Emwazi filed an appeal. And it is not known what steps were taken in response to Emwazi’s complaint.

According to a friend, Emwazi unsuccessfully tried to travel to Saudi Arabia to teach English in 2012. Soon after that, he disappeared.

Read related stories:

Related stories on Emwazi and the Islamic State