Crimewatch question

If anyone managed to watch Crimewatch last night, there was a part where two men had robbed a car and van somewhere in the Wirral, and then attacked another man who was in a bank. They dragged him out, dragged him to the floor and began kicking him. Fiona Bruce who was doing a voiceover said something similar to the following during the reconstructed beating:

"Due to security reasons, we cannot show you what happened next"

Now we all know how reconstructions can shock us, but later Crimewatch showed CCTV footage in Wales, of four youths attacking an innocent man. First hitting him in the head with either a fist or bat, and lead him to the floor. He was then beaten, and later stamped five times on the head by one of the youths. Before the showing, Nick Ross warned the viewers that they thought very hard about showing the footage, and decided that they had to, so they could catch the attackers.

It made me think that if they could show that CCTV footage, what could've possibly happened in Liverpool? I know it's best if nobody mentions what might have happened on TV Forum, but how can it be for Security Reasons?

Thanks

It may be that something specific happened which will form part of the questioning or evidence should someone be questioned/charged with the crime. On the other hand it may have shown how to carry out a crime of some sort.

the liverpool reconstruction was of a raid on a security van whereas the cardiff attact was unprovoked on somebody just walking down the street, therefore the first reconstruction would have to avoid showing anything which might jepadise the security company's employees in the future

Ah right. Thank you both.