Carnal knowledge is sexual intercourse between a male and female in which there is a degree of penetration of the woman's vagina by the man's penis. It is a necessary legal element of rape, child molestation, or consensual sexual relations with a female below the age of consent ("statutory rape"). State laws vary, but the age of consent is usually between 14 and 18.
The folowing is an example of a state statute involving carnal knowledge:
"Rape and forcible carnal knowledge:
1. Whoever of the age of seventeen years or older unlawfully ravishes or carnally knows a child under the age of eleven is guilty of a capital felony, punishable as provided in 775.082.
2. Whoever ravishes or carnally knows a person of the age of eleven years or more, by force and against his or her will, or unlawfully and carnally knows and abuses a child under the age of eleven years, shall be guilty of a life felony, punishable as provided in 775.082.
3. It shall not be necessary to prove the actual emission of seed, but the crime shall be deemed complete upon proof of penetration only."