Exactly 20 years since 18-year-old Stephen Lawrence was murdered at a bus stop in south London, his mother Doreen Lawrence has spoken about the progress of the investigation to convict her son’s killers.

She expressed her fears that the police will eventually move on from the case as a lot of money has already been spent on the investigation and the Met police have moved onto other incidents, such as the newspaper phone hacking scandals.

Talking to the Mirror, 60-year-old Doreen said:

Just having two of them caught will never be enough.

If there were five within the group that killed Stephen, all of them need to be behind bars. There was a rumour there were officers who felt they’d done enough and the investigation should be wound down. I think quite a few will think that’s enough because we can say 20 years on that not all of his killers are free.

Gary Dobson, 37, and David Norris, 36, were sentenced to life last year for the murder of Stephen Lawrence; 19 years after the offence, with Dobson recently dropping the appeal against his conviction and admitting to the crime.

They’ll say they’ve made significant progress in that time.

I don’t believe the officers involved in the successful investigation think enough has been done but I think others do and that I should be grateful.

But there’s nothing I should be grateful for.

They have a job to do and it’s their responsibility to bring his killers to justice, not mine. I shouldn’t have to campaign for them to do their job, that should have been done 20 years ago.

I presume at some point, they’ll say enough is enough. But I won’t be happy about that. If the police had done their job, we wouldn’t be here now.

The officers on the investigation now weren’t there in the early days, but as an organisation they have to take the blame for what happened. They need to accept whatever criticism is laid at their door.

A poster has been been put up outside the Scotland Yard to commemorate the anniversary, along with the message:

Twenty years ago the Lawrence family lost their son, Stephen. We let them down by not catching his murderers. Last year we finally brought two of his killers to justice. The Met won’t forget Stephen.