That doesn't make any sense! Someone came and talked to you, but you never saw who it was, then you have the number and name on a card, but came to look it up anyway, then tell about it. Do you know there is a special group of people that handles situations like that, called The Police.
"This person banged on my door in a Sunday night requesting for someone that does not live at my property" but then you said "We didn't get a look at her because we found her card at our front door" which also contradicts "this women appear to be sketchy.". So if you didn't get a look at her, how was she able to ask about someone who doesn't live on your property. Also, if you didn't get a look at her, then how could she "appear to be sketchy" and also how do you know that it was more than one woman? So many contradictions in that post, especially in a thread that seems to have been dormant for over a year and prior to those 3 posts was dormant for 3 years.
What company was he representing?? More information about the server would help. For some reason I doubt your story since we know how a process server operates and we also know the law about arrests.
So this woman was a police officer? She showed your mother her badge, right? Because I don't believe anyone other than an officer of the law has the ability to arrest someone.