As was pointed out in comments yesterday, it's hard to fully isolate dialogue from its tags and surrounding action. Perhaps "paying minimal attention to" is more accurate than "only critting dialogue." Maybe I should talk about the stuff around the dialogue, next time I'm at the helm of Unicorn Bell? :) I'll take requests...
Genre: Paranormal suspense
Set up (if needed): Jack is a local homicide detective, Stan is a friend with the FBI
Jack folded the paper and laid it aside, pushing up from his favorite overstuffed chair. He motioned to Mary that he would take the call in his den. When he picked up the extension Mary finished exchanging pleasantries and hung up.
“Hey, Stan. Thanks for getting back to me.”
“No problem. Afraid I don’t have much.” Stan’s voice held a note of apology.
“Whatever you’ve got.”
“Well, I couldn’t find much official on Harrison but I found people who know people. You know. Looks like Harrison works for one of those departments that doesn’t exist. At least not officially. Word is he’s into the weird stuff. UFO’s and little green men.”
Wait a minute, little green men? You mean like aliens? Come on , Stan.” Jack couldn’t keep the irritation out of his voice.
His friend snorted.
“What? You didn’t think we really have a department that tracks UFO’s and little green men? You never heard of Hanger 18 and all that shit?”
Here's why I crossed all that out: Jack would have had to be living under a rock for 50+ years to not have heard about alien conspiracy theories, X-Files, etc. More importantly, your readers would have had to, also. This is all old hat. Jack may not believe any of it, but he can be much more succinct about it -- which is why I left "Come on" in. Instead of this, Stan could be giving us more details/rumors or maybe Jack could rant a bit about conspiracy freaks. Whatever's in character for them.
Caveat: if this story is set in the 1950s or there's a valid reason Jack wouldn't know any of the above, the dialogue could stand as is. See next note.
Jack tried to set aside his instinctive disbelief. “So if Harrison is interested in our killer that means, what? This is a fairly current expression. It's why I'm assuming this is present-day. Harrison thinks he’s an alien?”
“Well, it’s not just aliens. They look into anything not normal like that.
“Why? I mean why are they hunting for these…paranormal types?”
“Hell, Jack. You sound like sound wide eyed rookie. Clunky -- it could be an inside joke, but those tend to condense down to as few words as possible. Re-phrase? What do you think they want? Chase ‘em, catch ‘em, and figure out how to use ‘em.” <-- Dialect, unobtrusively. Thumbs up.
Yeah, he knew that. He’d just never spent a lot of time thinking about it. But that was before.
A short silence spun out as Jack considered the implications.
“You got anything else on Harrison?”
“Not really. I got a little more but none of it good. People who have in contact with him, and there aren’t that many, say he’s really intense, maybe obsessed.” Kinda redundant.
“Obsessed? With what?”
“Again, no one seems to know. Then how do they know he's obsessed? At least no one I could find.”
“What about his pull? Where’s his weight coming from?”
The bright winter moon pulled Jack’s eye toward the window. Naked branches moving restlessly in the wind had taken on a sinister edge. Like a human lie detector. Like Cara.
“Pretty much everyone I talked to,” Stan continued, “said he’s got the power to make your life miserable, or mine. I got warned off all the way around. I don’t know what you’ve stepped in there, Jack, but be very careful. You don’t want this guy for an enemy.” This is all kinda redundant too -- it adds emphasis, yes, but I count three re-phrasings of the same information. Two would be enough, IMO, with "got warned off" as a spacer between them.
On the whole, this reads pretty well. The casual tone conveys a familiarity between Jack and Stan, and the addition of a little swearing brings a little tension toward the end.