When police arrived at the flat of Carrie Symonds in June, having been phoned by neighbours about an altercation they had overheard, it was familiar territory for police – not the flat or the couple concerned (Boris Johnson and Carrie), but being called out to a potential domestic abuse incident. In many forces 10% of all recorded incidents are related to domestic abuse and many calls come from neighbours, not those involved. In this case a neighbour “heard a woman screaming followed by “slamming and banging”. At one point Symonds could be heard telling Johnson to “get off me” and “get out of my flat””.

The incident sparked huge debate as to whether the neighbour should have called the police, whether the police should have attended and about what actually happened. Unfortunately it is often very difficult to work out whether a couple are having a one-off tiff, or whether a row is the manifestation of a unhealthy and abusive relationship. In the case of Boris and Carrie, the police left the scene having talked to the couple. Its not clear whether the police formally recorded the incident, did a DASH (risk) assessment and/or NFAed it (no further action).

Domestic abuse is any incident of “controlling, coercive or threatening behaviour, violence or abuse between those aged 16 or over who are or have been intimate partners or family members, regardless of their gender or sexuality”. It could include a husband throwing a saucepan at the wall during a row, a 16 year old boy shoving his 18 year old sister or something much more serious. In general the police are expected to attend every suspected domestic abuse incident in person. In the case of Carrie and Boris, two police cars and a van arrived within five minutes of the neighbours’ call.

Reports from HMICFRS (the inspectorate) criticise police for not arresting and not pressing for prosecution in domestic abuse cases. Domestic abuse is indeed a scourge on our society (and serious offences do of course need to be charged) but the evidence for arrest leading to a reduction in abuse is very weak and criminal sanctions do not reduce abuse.

So why is there such pressure to arrest (and not to use say an out of court disposal) in every case? I discussed this with Zoe Billingham, the lead inspector for domestic abuse. She pointed out that the “arrest by default” was backed up by College of Policing guidance. In her latest report the inspectors were “troubled that we found the number of arrests for domestic abuse-related crimes fell in 23 forces, despite the overall number of these offences increasing, often substantially. Forces need to be able to explain why this is happening, and ensure they are taking positive action to protect victims”.

In fact College of Policing guidance calls for positive action rather than arrest: “police officers have a duty to take positive action when dealing with domestic abuse incidents. Often this means making an arrest, provided the grounds exist and it is a necessary and proportionate response. Officers must be able to justify the decision not to arrest in those circumstances”. In our risk averse culture having to justify why you didn’t make an arrest means the pressure to arrest has teeth.

Many police are very unhappy about the College of Policing guidance and about the trenchant criticism they get from the inspectorate if not enough of their DA incidents turn into arrests. They think it fetters their discretion, doesn’t make sense and is not based on evidence.

I’ve looked at the evidence and it’s difficult to see that the positive action/arrest policy is justified. There is no study which looks at reoffending data which concludes that arrest itself is effective in reducing abuse – its not clear whether arrest or just reporting produces some positive impacts. There is only one study suggesting that arrest may lead to a reduction in abuse. This is from the USA and cites studies which are more than 20 years old.

So the only academic evidence we have for positive effects of arresting alleged domestic abuse perpetrators is one very old US study, and the rest of the evidence suggests arrest “appears to result in modest reductions in revictimisation, though the effect of arrest over and above police attendance is not clear”.

So why do the police inspectorate and the College of Policing still think police need to justify why they have not arrested domestic abuse suspects? The answer seems to lie in risk aversion. They believe that if the police had more discretion to use an out of court disposal or to divert/NFA, they may miss a serious coercive control relationship or the alleged victim may miss the opportunity to get support. They think “arrest creates what has been termed ‘space for action’ (see Kelly et al, 2013: 26) for the victim, a window of opportunity during which referrals can be made and specialist support services can engage”.

I can understand the risk aversion – domestic abuse is very emotive and challenging. And can lead to tragic consequences if handled badly. But the evidence to justify pressurising the police to arrest in every case is still weak. If needed, police can create “space for action”, without arrest. They can still refer victims to services and/or apply for a Domestic Violence Protection Order to prevent the alleged perpetrator accessing the family home or contacting the victim.

The reality is that huge police resources are being spent sending out emergency vehicles to, filling in 27 question DASH risk assessments and writing up reports of domestic abuse incidents, most of which don’t lead to a court hearing. And arrest and criminal sanctions don’t seem to be reducing abuse. Maybe we need to step back and use scarce police resources in a different way – train call centre staff to triage cases effectively so only the more risky and serious cases get emergency response, train police to spot the tell tale signs of a coercive but not physically abusive relationship, to improve referrals to victims’ services?

Some people think the police cannot be trusted. That, given more discretion, they will revert to treating domestic abuse as “just a domestic” and turning a blind eye. I don’t agree. There are ill-informed people in every force, but police attitudes to domestic abuse have reformed. Police officers make mistakes, and many haven’t had enough training (particularly in coercive control), but most take domestic abuse very seriously indeed. They only wish to be allowed more freedom to decide whether to respond to every incident as an emergency and whether to arrest.