Someone out there – perhaps someone reading this – knows who is behind the terrifying robbery spree on the River Lea.

Having heard first-hand what victim Ben Goodwin went through, I’m very relieved that he wasn’t more badly hurt. He was beaten up, knocked to the ground and threatened with a knife that, fortunately, was never produced. It could have ended differently; I’m in little doubt that Ben is haunted by that thought, too.

Ben is one of 11 victims these people targeted in just a few days. They preyed on individuals and small groups who were simply cycling or walking down the canal. In at least one case the knife was actually pulled out and held to a man’s throat. It’s nasty stuff.

That bit of the canal is a route I used to take every day on my bike – often after dark – because I lived just the other side of the marshes. My late shifts at the Evening Standard usually meant I would be crossing the bridge by the marina at about midnight. People were forever telling me to avoid the area at night but I never paid any attention. I got no trouble and it was a lot of fun speeding down Spring Hill in the dark. Now it feels like a lucky escape.

If these people aren’t caught soon, I fear something worse might happen. And while the responsibility for what they do is theirs, someone right now has the power to stop others coming to serious harm. Serial armed robbers are not people who should just be allowed to get on with it in the hope they get bored. Sooner or later stakes will be raised: someone will fight back, or something will happen in the heat of the moment that could not only change a victim’s life – or end it – but could turn these young men from robbers into murderers.

Their friends and family can stop that happening. But time is ticking.