Fewer than one out of every four defendants accused of rape in Northern Ireland was convicted last year, new figures indicate.
The 23.4% conviction rate last year was down slightly on the 25.7% recorded in 2015/16, according to the Public Prosecution Service (PPS), which has released a specific breakdown of rape statistics for the first time.
A number of the defendants acquitted of rape in 2016/17 were convicted of lesser offences linked to the same incidents. Of the 64 defendants who faced Crown Court trial for rape, 37 (57.8%) were convicted of at least one offence, with 15 of those (23.4%) convicted of the rape count.
The overall conviction rate for all types of offences in Northern Ireland is 86.4%.
PPS senior assistant director Marianne O'Kane, who heads up the service's serious crime unit, explained why the conviction rate in rape cases was relatively low.
"Rape is a devastating crime which presents many complexities when seeking to bring a prosecution to court," she said.
"Every rape case is different but they are all challenging to prosecute. The burden of proof is always on the prosecution to prove such allegations to a jury beyond all reasonable doubt. That is a high bar for a jury to reach, particularly when so many of these cases hinge on the issue of consent or the suspect's reasonable belief in consent.
"Although not essential to bring a prosecution, police and prosecutors will look for corroborating or supporting evidence which is often not available as alleged offences frequently take place in private and the complainant is the only witness.
"Rape conviction rates are historically and universally low across all jurisdictions when compared with sexual offences other than rape and with the conviction rates for offences generally in the Crown Court.
"The PPS has been working with other stakeholders to fully understand the reasons for this and seek to address them."
The statistics also looked at the number of rape files reported to the PPS by police last year.
There was marked increase (17.9%) in the number of rape files presented to the PPS in 2016/17 - 395 compared to 355 in 2015/16. In terms of all sexual offences, there were 1,313 filed passed to the PPS in 2016/17, compared to 1,245 the year before (a 5.4% difference).
Files received involved 1,399 suspects, 415 of whom were charged or reported for rape - a 17.6% increase on 2015/16.
A total of 1,087 prosecutorial decisions were made by the PPS in regard to sexual offences cases last year - with the evidential test for prosecution met on 36.7% of those files.
The average time taken to reach decisions increased significantly - from 187 days in 2015/16 to 229 days last year.
The PPS said the extended time frame was due to changes to the way evidence is obtained and proactive steps by the service, through the creation of the serious crime unit, to engage more intensively with alleged victims.
"The PPS is fully committed to robustly prosecuting these types of cases where the test for prosecution is met," said Ms O'Kane.
A retired Appeal Court judge has been asked to head up a major review into how serious sexual crimes are handled by the judicial system.
Sir John Gillen, who will be supported by an advisory panel, will examine a range of issues, including the disclosure of unused material; support for victims and witnesses; measures to ensure the anonymity of the complainant; the arguments for defendant anonymity; the impact of social media on trials; reporting restrictions; public attendance at trials.
Developments in neighbouring jurisdictions will also be considered.
Ms O'Kane said: "We fully welcome the recently announced review of how these cases are dealt with by the criminal justice system and hope that the publication of this statistical bulletin helps inform that process."