Bridget Sullivan with a dark side?

[snokkums]

I was watching "Lizzie borden took an axe" on the destination channel and I have a question about something the show said about Bridget. The show said when the police were asking the people that were in the house what did they know, when the police got to Bridget, the show introduced here as a maid with a dark side. What, if anything, happened to make the narrator make a statement like that? Was there something in Bridgets past that happened that would make the announcer say something like that? Or was it just because she was an immagrant,and an Irish Catholice immagrant at that? Or was it just make a good show?