You find a footwear print in cooking oil at a burglary scene. What is the best technique to collect this print?

Photographing the print at an oblique angle is the most effective technique in this scenario because it allows for the finest detail of the footwear impression to be captured. The oblique angle enhances the texture and any unique patterns in the print, which are critical for forensic analysis. In conditions such as cooking oil, the surface might not provide a clear impression, and capturing it photographically preserves the evidence without disturbing or damaging it.

Using tape or other lifting methods may not be suitable for fragile impressions found in a liquid medium like cooking oil, as lifting could potentially distort or remove crucial details of the print. Similarly, casting with a material would typically require a solid or semi-solid substrate to gather the impression effectively, which does not apply here. Washing the print with a solvent might also destroy the evidence, as the solvent could remove or alter the characteristics of the print that are necessary for identification. Therefore, photographing the print at an oblique angle provides the best method for preserving and accurately documenting the footwear impression for further analysis.