Victims of crime are not being properly supported by the Crown Prosecution Service, according to a watchdog.
Inspectors said communications with victims were slow in nearly half (43%) of a sample of cases examined.
Her Majesty's Crown Prosecution Service Inspectorate (HMCPSI) found too many letters sent to those affected by crime lacked empathy because they contain template paragraphs.
Chief Inspector Kevin McGinty said: "Victims and witnesses play a vital role in any criminal procedure, and it is important to make sure that their experiences are as positive as possible.
"One of the ways the CPS can achieve this is by communicating effectively.
"However our inspection has shown that in nearly half of the cases looked at, letters were not sent to victims and witnesses quickly enough.
"We were also told that victims felt let down by receiving what they see as a standard impersonal letter, which did not give them enough information to let them understand what has happened to their case."
Prosecutors are required to draft a short paragraph explaining the decision to discontinue a case or substantially alter charges against a defendant.
This is then emailed to a Victim Liaison Unit to be inserted into a letter to the victim.
The report said the quality of the explanations provided in these paragraphs was "variable and often inadequate".
Inspectors also found that in a majority of cases there is no evidence that victims are consulted before decisions are made to discontinue a case or substantially change charges.
CPS staff cuts and courts listing more than one trial in the same courtroom has put a strain on the ability of prosecutors to meet victims and witnesses before they are called to give evidence, according to the report.
It added: "There is a real risk that if victims do not feel supported they are less likely to attend court to give their evidence, thereby putting trials at risk."
The CPS said its national performance data shows a "markedly different picture" from the "small sample" in the report.
Chief Crown Prosecutor Martin Goldman said: "Eighty per cent of letters to victims due to reach them within one day meet the target and this increases to 89 per cent of letters due to reach victims within five days.
"Last year a survey showed that two-thirds of victims and three-quarters of witnesses were satisfied or very satisfied with the service they received from the CPS.
"We agree with the inspector that victims and witnesses play a vital role which is why we are committed to delivering a high quality service to victims and witnesses and supporting them throughout their case."