The autopsy.

Taken from http://search.gallery.yahoo.com/search/corbis?p=bullet&r=all

X ray had failed to detect any object in Markov?s wound.  However, following the autopsy, a section of the skin containing the puncture wound was found to contain a small metal pellet, 1.53 millimetres in diameter.  The pellet contained two holes 0.3 millimetres in diameter, drilled at right angles to each other.

Using scanning electron microscope, the pellet was found to be made of 90 per cent platinum and 10 per cent iridium, an alloy stronger than steel, impervious to corrosion and radio opaque, almost invisible on an X ray.

Radio opaque materials have a use in medical science as markers.

The pellet pointed towards the use of poison, but was there any more evidence for this?