Most rapes occur at weekends or during the summer holidays when people are socialising and drinking more alcohol, a conference in Letterkenny was told yesterday.
Garda Sgt Bobby Mullally, who examined available statistics, said the number of reported rapes had peaked in 1998 and was now on a downward trend.
Further research would be needed to find out the reason for the 1998 increase. Up to 300 rapes were reported to have occurred in that year in the State, he said, but not all those reported to garda∅ ended up in court for various reasons.
He was speaking at a conference on "The Reception, Care and Medical/Legal Aspects of Rape/Sexual Assault" organised by Letterkenny General Hospital.
The aim of the two-day conference is to bring together all the professionals working in the area of rape and sexual assault, including medical staff, social workers, garda∅ and forensic scientists.
A dedicated sexual assault treatment unit was opened at Letterkenny General Hospital in 1998, the only such facility outside Dublin and Cork.
Ms Anne McHugh, who helped set up the unit, said it provided a safe and sympathetic environment where victims could be assured of privacy.
The Garda, in an unusual step, have been given a key to the unit, so victims could be taken directly there after reporting the crime.
Dr Louise McKenna, from the Department of Justice's forensic laboratories at Garda Headquarters, detailed the type of information needed by scientists from medical examinations of sex assault victims.
While most rapists were known to victims, forensic science was particularly helpful in identifying perpetrators of stranger rape.
She outlined the importance of looking for traces of the attacker's saliva on the victim's body and of doing nail scraping on the victim to help identify the attacker using DNA testing.
Dr McKenna said traces of semen were found in only 50 per cent of cases and it was therefore important to look for traces of other body fluids. She said the forensic laboratories dealt with more than 500 cases of rape and sexual assault a year.
A forensic clinical nurse specialist from California, Ms Sharon Crowley, spoke about the use of colposcopy in examining sex assault victims. She said it was a non-invasive procedure and its advantage was that it magnified injuries that might not be visible to the naked eye.