Thank you for your letter of 17 January 2008. I have now received a report from Mr Mike Kennedy, Chief Operating Officer.

I am pleased that your Committee found Sue Hemming's evidence of assistance but note that further information is required on the genesis and application of the Threshold Test. To assist in this, I have enclosed, as requested, a copy of the internal guidance concerning the Threshold Test which was issued to crown prosecutors in August 2005.

As might be expected, there are a number of police investigations which do not produce sufficient evidence to satisfy the Code for Crown Prosecutors' realistic prospect of conviction standard within the pre charge custody time limits but there may clearly be further significant evidence to be obtained. The dilemma facing the police and crown prosecutors in a limited number of these cases is that a proper risk assessment reveals a dangerous suspect or one that would, if released, flee the jurisdiction or interfere with witnesses or hinder the recovery of evidence.

The statutory framework provided by the Police and Criminal Evidence Act 1984 (PACE) does not provide for any specific interim assessment to justify charging in such circumstances. Prior to the changes brought about by the Criminal Justice Act 2003, PACE allowed the police to charge on a rather vague notion of there being 'sufficient evidence to charge'. This standard is not defined in the Act and bears no relation to other more objective standards such as 'a realistic prospect of conviction' or 'beyond reasonable doubt' as required to satisfy a jury. Rather it provided a standard that was as flexible as the circumstances required.

It is a matter of history and part of the methodology of police working that their pre 2003 charging decisions were largely based on oral exchanges between the investigating and custody officer, occasionally supported by documentary evidence, but often with much of the key evidence that would now be necessary to satisfy the requirements of the Code for Crown Prosecutors still to be obtained. The low evidential standard demanded by 'sufficiency to charge' facilitated a generous interpretation and for the dangerous offender dilemma to be dealt with pragmatically.

The application of this standard to casework led to high levels of discontinuance and many aborted trials, even in cases where defendants had been held in custody. This was mostly due to the failure of the police to produce any additional necessary evidence or a failure to produce it within a timetable acceptable to the court and the interests of justice.

This was one of the reasons underlying Lord Justice Auld's recommendations for the transfer of responsibility for charging to the Crown Prosecution Service (CPS). For this purpose, the Criminal Justice Act 2003 empowers the Director of Public Prosecutions to issue guidance to enable custody officers (and crown prosecutors) to decide how persons should be dealt with when a custody officer believes there is sufficient evidence to charge a person.

Guidance for crown prosecutors has also been published by successive Directors of Public Prosecution (DPP) under the Prosecution of Offences Act 1985 through the Code for Crown Prosecutors. The Code is published after wide public consultation and since 2004 has included specific guidance on how crown prosecutors should determine whether and what to charge. The required standard to charge is set by the DPP and can be changed should the circumstances demand it following consultation. The current standard is designed to protect potential defendants from being charged with weak cases where there is no prospect of a successful prosecution and to prevent the wasteful expenditure of public money.

As part of the strategy for dealing with the annual one and a half million prosecutions, I decided that the CPS should charge the more serious and complex cases, with the police dealing with volume straight forward admitted lower level offences. It was clearly inappropriate for the police to be able to charge on a different standard from crown prosecutors and I required that the police charge using the Full Code Test of there being a realistic prospect of conviction. Indeed the 2003 PACE Codes of Practice made this a requirement. This split of work naturally meant that crown prosecutors would make the charging decision for cases where the intention was to seek a remand into custody post charge.

The Code for Crown Prosecutors requires that assessments of cases to be charged are based on a proper review of the evidence. This requires the production to and assessment of statements or other evidence by crown prosecutors. This increased standard of scrutiny has led to dramatic reductions in the discontinuance of cases and the number of abandoned trials. It did however raise the issue of what to do in cases where the PACE detention clock, with extensions, defeated the ability of the police to produce sufficient evidence to charge to the Full Code Test standard.

In cases where the suspect was suitable to be released on bail, there was no issue since the suspect would be so released while the investigations were completed. However, the issue with the offender who is a bail risk or a risk to public safety is obviously much more difficult. Let me provide you with a hypothetical example of the dilemma facing the police and prosecution, although recent examples of those who have allegedly killed while on bail is example enough of the tragic consequences that can arise.

Typically the profile which is often considered is that of an offender who presents as an alleged deranged axe murderer. The evidence at the critical time is not sufficient to pass the Full Code Test as no forensic examination results have yet been received on blood and other items recovered from the scene. However, let us say that the suspicions are based on the recovery of an axe from an area associated with the defendant who provides a no comment interview. There is at present no further evidence. From the above, and from enquiries and other evidence yet to be obtained, there is now at least a reasonable suspicion that the police have arrested the right man. The police believe that these other enquiries and the laboratory results are highly likely to link the man to the scene of the crime. The retention in custody of this man in the meantime provides the opportunity to avoid the risk of the loss of further life or serious injury which from the indications and risk assessment the police have made seem a distinct possibility.

The Threshold Test was developed to deal with this dilemma and is fully compliant with Article 5 of the European Convention. The effect of any charging is to bring a suspect who on reasonable suspicion has committed an offence promptly under the jurisdiction of a court. That court's sole or principal concern will be to determine whether the suspect should be bailed or remanded in custody. The Threshold Test goes beyond the Article 5 requirements by requiring that there is a future realistic prospect of conviction through the obtaining of further identified significant evidence within a reasonable time.

At any such hearing, the court and defence will receive at least an outline of the case and the reasons why the prosecution will be seeking a remand into custody. Case progression rules require an explanation for the delays being sought which in the above case would be the need for further enquiries and examination of the laboratory results. The strength of the evidence is a factor the court would take into account under the Bail Act which the defence would be free, as they do, to exploit on their client's behalf. The court would then determine whether the prosecution's application could be sustained.

The Threshold Test itself has already been explained to you; its precise wording is to be found in the Code for Crown Prosecutors. It is applied objectively by the charging crown prosecutor and is based on the evidence produced by the investigator and the evidence to be obtained. It can never be founded on inadmissible evidence, mere intelligence or intercept material, for which in the latter case there is specific statutory exclusion. The onus on the crown prosecutor is always to apply the Full Code Test of the Code for Crown Prosecutors. If this cannot be done, then the suspect must be bailed while the required evidence is obtained. Only exceptionally if the suspect on a proper risk assessment is not suitable to be bailed, even with conditions, and the objections to bail can be sustained at court will the Threshold Test be applied.

The Threshold Test itself was developed for the generality of casework and not for any specific cases such as those charged under the Terrorism Acts which represent a very small percentage of the CPS's business. It is an open, transparent and accountable process and the CPS is following its published policy set out in the Code for Crown Prosecutors. At every initial remand hearing, a copy of the evidence or a summary is disclosed to the defence. The reason for its application is as explained in this letter.

The PACE review currently taking place is to be asked to reassess the workings of Section 37 of the Act which provides the current statutory standard of the evidence justifying charge so that it and other drafting issues criticised by the judiciary can be clarified and improved in possible future legislation.

I trust the information contained in this letter will provide the detail you and the Committee require.