A new smartphone app developed by Sydney experts will help witnesses and victims of crime record information that can later be used in court.
Memory experts hope a new smartphone app to help people record information after witnessing crimes will lead to more reliable testimony in future court cases.
iWitnessed, launched on Tuesday, uses guided questioning to prompt users to record facts about an event including its nature, location, whether there were injuries and the witness's emotions at the time.
The content, which can be taken as text, voice recordings or images, is also time and GPS stamped with the option to forward a copy to police or a secure email address.
The app has the backing of former NSW Director of Public Prosecutions Nicholas Cowdery QC, who says the content could be relied upon in court in the same way as contemporaneous notes or recordings to refresh a person's memory.
"Contemporaneous notes, even if scribbled on the back of a napkin, can strengthen the reliability and strength of the evidence being given in court proceedings," he said in a statement.
The free app was developed by researchers from the University of Sydney and UNSW, who consulted with police and lawyers.
Dr Helen Paterson, a senior forensic psychology lecturer at the University of Sydney who worked on the project, says recalling an event within 24 hours of when it occurred helps consolidate a memory.
"That's a critical time period - that's what our research has shown," she told AAP.
"You have to try to give it as soon as possible after the event, but within 24 hours."
The recall process can also help a person resist misinformation later on, for example in a police interview that includes leading questions.
The app includes an "emotions" tab for users to record how they felt at the time - an addition that came about after police suggestions.
"That can have implications for prosecutions," Dr Paterson said.
"For example, if you feel intimidated or scared, that might mean different crimes have been committed."
Lawyers frequently question the reliability of witness memories as part of a defence argument, particularly when a trial takes place many years after a crime.
Dr Paterson said she hopes the app will help courts get to the truth of the matter.
"I hope that it's going to lead to more reliable testimony in court."
iWitnessed can be downloaded from the Apple or Android app stores from Tuesday.