IP Address & Cyber Monitoring Question

I have a cyber stalker. I know who this person is and already have a "limited contact" order in place against him, but unfortunately when I have contacted local authorities about this, they say that this person has not broken any laws so there is nothing they can do at this point. The person has not threatened me, but seems to have a strange ability to always know what I am doing online and often "reports" to me what I have recently done.

I have reason to believe that this person entered my home when I wasn't there and installed a key logger or other monitoring software on my computer due to how much this person seems to know (and shouldn't). Are there any programs or apps I can download or purchase that will sniff out any monitoring software that this person may have installed on my computer?

Additionally, I received an odd email response to an ad I recently placed on Craigslist. I found addresssearch.com and used the reverse email lookup feature and discovered that the 2 IP addresses associated with the email I received are the same IPs that I have previously traced back to the person who is "following" me online. What are the odds that these IP addresses associated with this email addy are someone else if the ISP uses dynamic IPs? To me it seems like it is a very unlikely coincidence that I have been approached by two different people in two different places with the same IP, but I am not computer savvy enough to be sure of that.

I am hoping that I am just being paranoid, but I don't think so.