Someone explain the ending of the pilot

I'm not sure which part needs explanation.
1 - The very resourceful "perp" (Eric) was able to acquire the home address of a City of Pittsburgh detective.
2 - Eric was able to gain access to secure building which is home to detective.
]3 - Eric was able to extract an unconscious Catherine from her building without being noticed.
4 - The following morning Detective Molbeck and the forensic psychologist/profiler (Schaeffer) were able to ascertain the Erics back-up holding location in another county
5 - Detective Molbeck and Schaeffer were able to make their way to another county before any other police
6 - DetectiveMolbeck subdued Eric while Schaeffer rescued Catherine
7 - A rescued Catherine jeopardizes the safety of all involved to play mind games with Eric
8 - Mind games fail and Detective Molbeck is stabbed by perp
9 - Catherine shoots Eric to save Detective Molbeck
10 - Catherine orders Schaeffer to get the wounded Detective Molbeck "out of here"
11 - Alone with Eric, Catherine continues mind game
12 - Eric still doesn't want to play and is shot several times by Catherine

13 - Schaeffer opens package containing scarf with note saying "you forgot this"
14 - Schaeffer is confused and upon further examination of the box, finds a large envelope
15 - Schaeffer wonders "what could be in this envelope" for far too long before opening envelope
16 - Finally a copy (or perhaps the original, but that is unlikely) of the strangely folded photo that Schaeffer saw in Catherine's apartment is taken from the envelope. "It was my house" - was printed on the lower left corner - this was the answer to the question the Schaeffer asked Catherine when he was looking at the images of the homes of serial killers in her apartment. The Schaeffer unfolds the envelope and sees, "This is why I found you" printed above the image of a man (Catherine's father).

So was that envelope and all sent by Catherine or what? And why did she look evil at the end

Thanks so much! You're awesome