Pre-transfusion samples
Unless indicated for blood-borne virus screening, there is no requirement for pre-transfusion blood samples to be taken from victims of sexual assault and rape.
Should the police request this, it should be undertaken by a suitably trained medical professional who can assure the chain of evidence; this is usually the forensic medical examiner.
Other investigations
Other investigations should be requested and acted upon in line with clinical need; for example, a group and save or crossmatch might be requested for a patient who is catastrophically bleeding, or a CT facial bones might be performed in a patient with evidence of facial trauma.
Learning bite
Routine swabs to screen for sexually transmitted infections should be avoided, as they may disrupt forensic evidence and are unlikely to return a positive result so close to exposure.