What constitutes aggravated indecent assault?

Aggravated indecent assault specifically involves sexual actions that go beyond simple acts of indecency. The concept of penetration refers to the act where any part of the defendant's body is used to violate another person sexually. This is particularly significant because penetration indicates a more severe breach of consent and bodily autonomy compared to other forms of sexual assault that might not involve such direct bodily invasion.

In distinguishing this from the other options, consider that assault with a deadly weapon involves the use of an object to threaten or harm but does not inherently involve sexual assault. Similarly, while penetration with an object could imply an invasive act, it doesn't encompass the more personal nature of using one's body in the act of aggression. Lastly, assault resulting in injury focuses on the physical harm caused to another without necessarily implicating sexual intent or the specific nature of the act, which is critical in defining aggravated indecent assault.

Thus, the correct identification of penetration with part of the defendant's body encapsulates the essence of aggravated indecent assault, making it a pivotal element in understanding the severity and classification of this crime.