Study on development of forensic blood substitute: Focusing on bloodstain pattern analysis.

Bloodstain pattern analysis, one of the areas of forensic science, is performed to analyze the physical characteristics of bloodstains, including their size, shape, and distribution, to reconstruct a crime scene. A bloodstain pattern analyst should obtain through experiments and education the capabilities to both understand the generation mechanisms of bloodstains and identify the characteristics of the bloodstains. Experiments and education about bloodstain pattern analysis are carried out by using human blood taken from subjects, animal blood (porcine or bovine) supplied from butcheries, and blood substitute products developed in other countries. However, these kinds of blood have many limitations in their application due to various problems. The blood substitute developed in the present study is more similar to human blood than other blood substitute products developed in other countries with regard to the physical properties, including viscosity, viscoelasticity, and surface tension, as well as the drip bloodstain patterns depending on the surface and coordinate characteristics of drip stains impact angle. The blood substitute developed in the present study is more practical, because the materials that are used in its preparation are readily available in the market and do not include chemicals that are harmful to the human body, and the blood substitute has luminol reaction functionality and pattern transfer bloodstain (bloodstain fingerprint, bloodstain footprint, etc.) dyeing functionality.

A Ferris Wheel Accident at a Movable Amusement Park.

This study presented a Ferris wheel accident case. A Ferris wheel is composed of many parts, and the outmost ring of it is assembled using a lock pin. This accident occurred because the lock pin caught the door of a gondola and the gondola overturned. Five of the seven passengers in the gondola fell to the ground, along with the gondola's viewing window. The investigation revealed that the gondola became stuck when its door was caught by a lock pin at the Ferris wheel's three o'clock position. The contact between the door and the lock pin was due to a structural problem: There was not enough space allotted between the door and the lock pin. Therefore, if a passenger pushed on the gondola's door, the potential existed for contact between the door and the lock pin.

Pedestrian accident analysis with a silicone dummy block.

When a car is parked in an inclined plane in a parking lot, the car can roll down the slope and cause a pedestrian accident, even when the angle of inclination is small. A rolling car on a gentle slope seems to be easily halted by human power to prevent damage to the car or a possible accident. However, even if the car rolls down very slowly, it can cause severe injuries to a pedestrian, especially when the pedestrian cannot avoid the rolling car. In an accident case that happened in our province, a pedestrian was injured by a rolling car, which had been parked on a slope the night before. The accident occurred in the parking lot of an apartment complex. The parking lot seemed almost flat with the naked eye. We conducted a rolling test with the accident vehicle at the site. The car was made to roll down the slope by purely gravitational pull and was made to collide with the silicone block leaning against the retaining wall. Silicone has characteristics similar to those of a human body, especially with respect to stiffness. In the experiment, we measured the shock power quantitatively. The results showed that a rolling car could severely damage the chest of a pedestrian, even if it moved very slowly.