The cut ends of the padlocks shackle had lightly rusted, which obscured the fine individual characteristics. (photo #1)
The results were that the light rust was sufficiently removed in order to make an identification, that the pair of suspect bolt cutters had in fact cut the padlocks shackle.
The name of the laboratory cannot be mentioned in the above article. However, it would be fine to say this information was “From a major forensic crime laboratory”.