[crystaln]

Indeed. Parallel construction is when law enforcement doesn't want to burn their source or their source is unlawful, so they find another way to justify a warrant or prosecution even tho their initial justification comes from a different source.

This has been upheld as lawful, but also can unfortunately be used to disguise unlawful behavior.

Reverse engineering is not related to parallel construction.

[crystaln]

Parallel construction would be if LE unlawfully intercepted transmissions using this technique and discovered a crime, then found other unrelated evidence to begin an investigation of that crime.