She was allowed to make a plea bargain that Bernardo's lawyer later called a "deal with the devil".
The police had spent days searching the Bernardo home bur failed to find video tapes hidden in a light fixture in a false ceiling. The deal with Homolka was made in ignorance of the contents of the video tapes.
Bernardo was able to continue his rampage because the police departments involved failed to keep each other informed about crime sprees going on in their own patches.
A Royal Commission rapped the police forces involved for being jealous of their own turf.
Bernardo was never tried for the Scarborough rapes, to the disappointment of senior Crown attorney for Scarborough Mary Hall (known as Maximum Mary). Hall also wanted to prosecute Homolka for her participation in one of the rapes. Her vociferous objection to a second plea bargain that gave Homolka immunity for crimes including that rape got Mary Hall removed from her office.
This was under an NDP Ontario government. Such is the way that left wing governments operate,