Detective Superintendent Matt Fenwick, who led the police probe after Mr Greaves was discovered badly beaten near his home, said it was “the most shocking and emotionally difficult investigation” he had experienced in his 26 years as a police officer.
He said: “When you deal with any crime one of the first things you look for is the motivation, that gives you a good idea as to who the offenders are. With this case we haven’t established the motive, we just believe they have done it because they can, for no other reason.
“That in itself makes it a very complex investigation. From the outset we had no idea who could have done something of this magnitude so we had to undergo a very complex investigation.
“No one is denying we have got the right people, no one has denied that they are the people on that CCTV footage. What has been disputed is who did what and Ashley Foster has been saying he didn’t do it. He is saying he is one of the two on the CCTV but has denied being responsible for it.”
Mr Fenwick described Jonathan Bowling, 22, who admitted murder at an earlier hearing, as a “very violent individual”. He said: “He has committed the most horrendous crimes, in my view. His capacity to commit these types of crimes means he needs to go to prison for a very long time, if not the rest of his life.
“Foster and Bowling are known to the police in that they both had previous convictions, we knew who they were and the type of criminals that they were. Did we realise they had the capacity to commit a crime like this? No, we did not.”
Speaking outside Sheffield Crown Court after the trial, Mr Fenwick said Mr Greaves’s family “displayed great strength and dignity in such ghastly circumstances” after his death.
He said: “I can only hope that today’s verdict will bring some small solace to them as they continue to come to terms with losing Alan in such tragic circumstances.”