The manuscript is poorly punctuated.  For instance, there are far too many commas, and some commas in wrong place. (See  markings)

Poor paragraph construction.  Some sentences not clear.  To be blunt, some of your sentences make no sense.  Look for the markings.

Too much author intrusion. By that I mean, instead of being in your character’s head, you, the author, are intruding with explanations.  For instance, on Page 3 you write:

She went across the Bay Bridge (San Francisco to Oakland) to visit her sister.

Another example on page 5:

She wanted to attend a Forty-Niner's game (professionl football)

    Such intrusions disrupt the flow of the story.  Not only that, readers are smarter than you think.  You insult them when you explain something they already know.  Even if they don't know, it's not up to you, the author, to intrude and tell them.

    Mysteries and thrillers do not begin with long, boring descriptions. They need a "hook" on or close to page one.  Otherwise, the reader loses interest. Murder in the Fog begins with ten tedious, wandering pages describing a foggy Christmas in San Francisco.   I doubt you would have one reader left by the end of those ten pages and would highly recommend you eliminate about 99% of all that description.   Cut  to the chase, as they say.

    At one point in your chapter you describe Santa's elves dancing around a Christmas tree in Union Square.  Murder mysteries--and I assume that’s what you’re writing--are starkly factual.   Santa's elves belong only in fantasies.

    What tense are you writing the story in, present or past? You are jumping from one tense to another, sometimes in the same paragraph.  Not a good thing.

    What person are you in? First  Second?  Third?  You have used them all.  Again, not a good thing.

    When you finally get to your description of Jane, your heroine,  it is far too brief. You should introduce your protagonist on page one.  Not only that, readers can suspend credibility to a certain extent, but Jane's motivation for getting herself dangerously involved in those gruesome crimes is skimpy at best. I would guess most readers would find her motivation totally unbelievable.