I think we have been thrown a Red Herring (again). The cop was actually trying to get revenge for something - probably other Emma. He is not a stalker, and definitely not a henchman of "the bad guy".
Of the possible stalkers my no2 is Lucy. She is obviously envious/jealous of Charlotte so it could be a play on her part.
So we have at least 2 more critical situations, assassination attempt and stalker uncovering.
Emma on the other hand, and I see no one mentioning the fact, has put MC contact in her phone as "Dad" (scene when she drops the phone after Carter attack) . It would require some mental gymnastics to turn her into a LI, without Charlotte leaving the picture (as in being assassinated, god forbid).
Lucy has the "film Noir" feel to her, instead of Kayla (who would be the obvious famme fatalle), so I think the ending for her is not going to be a good one.
Suzy is currently so far out of the picture, that only ending of episode 10 can affect her and bring her closer to MC