Sexual assaults can be facilitated by the use of drugs, both "street" and legal. While alcohol is often a factor in sexual assaults, illegal drugs (also called "club drugs") can also be a factor. Some victims are drugged without their knowledge when the drugs are slipped into their drink. Some of these drugs are tasteless, odorless, act as a quick sedative, and usually cause amnesia and/or a loss of consciousness that may last anywhere from several hours to several days. These drugs have been misused to involuntarily sedate individuals in order to commit sexual assault. These drugs are often referred to by a number of street names.
The only way to be sure that a person has been drugged is by testing their urine or blood. Every hour matters. Chances of getting proof are best when a urine/blood sample is obtained soon after the substance has been ingested.