Final answer:
The femur is the most helpful bone in determining the sex of an individual at a crime scene due to differences in male and female skeletal structures.
Step-by-step explanation:
The type of bone that would be most helpful in determining the sex of the individual is the femur. The femur, or thigh bone, has characteristics that vary between males and females, with males typically having a femur with larger and more pronounced structural features due to generally greater muscle attachment areas. Additionally, the angles of the femur relative to the pelvis also differ between sexes. When examining bones, the pelvis as a whole is one of the best indicators of sex, with the sub-pubic angle and the shape of the pelvic cavity being quite distinct between males and females. The pelvis bones, specifically the ilium, which forms the superior part of the hip bone, are also valuable in sex determination.