Jim 
I chose to review your item today as part of my review challenge at the
"Invalid Item" 
. The 'Dark Sci-fi' tag caught my attention. Dark=good. Sci-fi=good. Together=Awesome!
Synopsis

A respected quantum-physicist is arrested after propositioning several women. The interrogating detective learns an experiment had gone wrong would soon destroy the earth and the scientist was trying to live out his fantasies.
First Impressions:

I have to say the ending was one of the stronger ones I've read on this site. Fantastic. There also was enough tech language to make it believable without losing the reader and turning it into hard-scifi.
Suggestions:
I try to give as many suggestions as possible so the writer can pick and choose anything they feel would help their story. Some of it might be from a technical point of view, like I was an editor, or they are things I simply felt as a reader, but please take it all with a grain of salt.
In General:

The characters and plot were strong enough that there's not much to offer for suggestions, but I found there were several sentences that could be improved and therefore improve the story as a whole. There were a few parts where Kevin wavers between no emotion and breaking down. This reaction is believable in this situation, but I found it came across more like clinical mental instability rather than a man struggling with the end of days. But this was just my reaction as a reader.
Specifics:

Detective Osborn was
puzzled at Kevin’s insistence
(There's actually nothing wrong with this but the word puzzled feels out of place with the character. It's also a tad 'tell'. Perhaps working it into dialogue)

Men who
had done acts such as
he’d done usually ended up in court.
(Slightly repetitive)

you propositioned several others; you knew each one of them, and each time, the same result.
(Order puts off the flow. Perhaps reword)

Detective Osborn only responded when he realized that Kevin wasn't going to say anything more.
(You could put a comment about silence before this part to make more time pass and this sentence stronger)

It took an incredible amount of willpower to regain control of his feelings.
(This sound more like Kevin's POV)

You don’t fit the profile of a perv,
the kind of person who normally does what you’ve done. (The first part is one of my favorite lines but the second part suggests that the title of perv is only for those who propositions women)

His voice was so soft that Osborn
found himself leaning close to Kevin to hear what was said.
(Something like "Osborn had to lean in to hear...", to me, sounds better)

He began to speak, his words
slow at first,
then picking up speed. ('Slow at first' already suggests he will pickup speed)

Recently, we began to collide protons at
higher and higher energies
(This doesn't sound like something a professor would say. 'At increasingly higher speeds" or something like that)

Kevin continued to
speak, his
speech flowing smoothly, information
pouring out of him now.
(Each of these sentences sort of suggest the same thing.)

it would essentially explode
into a much larger size (Sounds off. Perhaps reword)

Kevin continued, becoming agitated as he spoke
more and more.
(Sounds strange, to me)

Osborn couldn’t stop the exclamation that escaped from his mouth.
(I think the "Ten days!" is enough this line doesn't need to be in there)
Favorite Lines:

You don’t fit the profile of a perv,
(ha! Perv. Don't know why, but it's a great word choice)

it was immediately swallowed by the first one, doubling its size.
(All I could think of was, "Oops.")

There are several things I’ve always wanted to do, and those women had always excited me.
(Can blame the guy for trying
)

“Good luck, Dave, but I think it’s too la--“
(Best line!)
All in all:

A great short story and one of the few hard(ish) sci-fis I could follow. Well done!
Thanks for sharing your work. Keep writing and good luck!
Robyn