This is from a Guardian article when the HPU was set up in 2004. If only they’d give these things a chance we might make some progress 
It is headed by Laura Richards, a senior behavioural psychologist, whose team of analysts works with detectives on current inquiries as well as researching trends and interpreting information about high-risk offenders.
The analysts will also look at "near misses" - attempted murders and serious assaults which could have resulted in death.
Experience has shown that many murderers have a pattern of offending which begins with relatively minor crimes and grows increasingly violent until the offender rapes or murders.
Such offenders may also have had disturbed childhoods. Mr Baker said FBI research revealed that many children who grew up to be serial killers had begun by torturing animals.
Ms Richards, who has carried out extensive research into domestic violence, said those who abuse partners were much more likely to commit violent crime outside the home - as did the Soham murderer Ian Huntley and the M25 rapist Antoni Imiela. One in 12 domestic abusers has convictions for sex attacks on strangers.
"Violence doesn't occur in a vacuum," Ms Richards said. "Violent acts are often a culmination of long-term development, identifiable trails of problems, conflicts and disputes."
Potential offenders may begin carrying weapons, perhaps using "trial runs" of their fantasy crime scenarios to build up confidence before going through with them for real. Location and opportunity can also be important.
Ms Richards said analysts had to read the criminal's inner thoughts to try to work out how these could escalate. It was often more about the "quality" of the violence - the significance it held for the perpetrator - rather than the quantity.
In common with many domestic abusers, some murderers could be charming and cunning, and extremely adept at manipulating people, including police. "It's about asking the right questions and knowing how to interpret the answers," she said
www.theguardian.com/uk/2004/jul/05/ukcrime.rosiecowan