Today we need the public to help us trace Jamie Marsh-Smith. We are keen to speak to him in connection with the murder of Zafer Eren.
We know that allegiances shift over time and now months on from Zafer's murder, people may have the confidence to talk to us.
A £30,000 reward is available for information that helps us arrest and convict those responsible for Zafer's death.
More top news
The 52-year-old had previous convictions for violence but was not on the anti-terror watchlist.
In a statement Charlton Athletic said: Keith was a true hero who will be greatly missed by all the Charlton family and everyone at the club.
London and the worlds has united on Twitter in defiance of the West minster attack #prayforlondon #wearenotafraid