At that range, a fairly small crossbow, such as the cutesy pistol crossbows, would be enough. Also, at that range, and considering the angles, if the shooter were to extend their arm with the crossbow just before shooting, the actual range would be closer 5-6 feet. At that range, a neck shot is quite possible. Likely it wouldn’t be instantly fatal, and the victim would stumble and thrash about a fair bit before bleeding out, making a bloody mess of his apartment, and giving superficial indications of a struggle.
Oh my God, Perderabo, I laughed so hard I almost fell out of my chair. That was too funny…(wiping tears from eyes)
test
Once again, I find myself indebted to you all. Thanks! (Tranquills–nice info)
warmgum:
I’m guessing you passed the test?
-I probably will save the fish as a murder weapon for a future story (seriously - I periodically have editors ask for strange weapons [never a fish however])
Your murderer need only have access to some manner of lab facilities (hospital, university, etc.) to be able to manufacture an ultra-cold icicle. There’re freezers everywhere, and nobody’s going to notice an extra box in one. Took me about 10 minutes of searching to find what I was looking for in the six freezers of our lab this morning. And we don’t even have our own cold room. So…I wouldn’t let limited access stop you. And it’s gonna take a damn long time for that thing to melt, unless it’s really slender. Even a medium sized chunk of dry ice takes a while to sublimate at room temp.
-ellis
Dry ice is readily available, althought the number of suppliers in any particular area tends to be low. It can be worked with a “hot wire” cutter, similar to the ones used for cutting and shaping styrofoam. Buy three pounds of it, in one pound blocks, keep it in it’s insulated bag and place the bag in a good quality cooler. it should keep for a fair while. The last time I worked with dry ice, I was shrinking a generator stub shaft for bearing replacement, and we bought 5lbs, cut by the supplier into 6"x1"x1" chunks. It took a good two hours to get set-up for the bearing replacement, and the rods of ice were still almost their original dimensions.
Alternatively, make your ice-bolt from water ice (freeze a test-tube full of water?), then pack it in dry ice in a cooler on the back porch to freeze it down to the point where it becomes much tougher. Use one of the 45-lb draw pistol-stlye crossbows, and you’ve got a nastly little device. Here’s an even more convincing beast, complete with collapsible stock.
Possible give-aways to the scheme: Insulated bag with dry-ice supplier’s logo on it, pawnshop records of a purchase of pistol-style crossbow, unsual quantities of water in blood, unusual flow patterns of blood, or maybe just a puddle water off by itself with a little blood and machine oil in it.
Here’s what you were looking for:
Trident II
Maybe I should be kept away from locked rooms for a while…
The cute little device perched atop the Trident II crossbow is a point-sight, probably one made by Daisey. A little light at the back of the sight relects off the glass lens, allowing you to line-up the bow with the target. It doesn’t produce a visible beam, and for the distance you’re talking about would pretty much guarantee a hit anywhere you want it.
TV Time, could you tell us your name? i want to buy some of your books! anyone who would consider a fish as a murder weapon is someone i want to read.
Yeah, TV, I passed the test but the GQ board didn’t!
I posted after Tranquilis but noticed it didn’t bump up or show me as the last poster. I gave it some time and still no go, sooooo I went to ATMB to ask why but it wouldn’t let me start a new thread. I came back to GQ still showed Tranquilis as the last post so I did a test post. It still didn’t register. Disgruntled, I left for a while.
I’m happy now though 
With a point sight, and a short range, you no longer have to rely on the victim knocking the window prop out of the way. It can be shot away with a second ice-bolt. This removes a chance element that might spoil the killer’s planned “locked room”. It would, perhaps, create additional elements for figuring out what really happened: Why does the window prop have this big fresh scar on it? Or maybe the prop broke in two and part of it was trapped in the window when the windows slammed shut (bits of broken window prop sticking out from under the closed window ought to get someone’s attention). Perhaps someone (a dog walker, a nosey neighbor, etc) heard the window slam and saw something?
I’ll shut up now. I can’t wait for this to hit print, to see where you went with your ideas, and how it all shakes out. Please let us know when it’s published?
Pretty please?
You see, the killer doesn’t want a locked room. He wants at least two possible murder suspects to put him well down if not off the police’s list of possibilities. The door bolted from the inside somewhat eliminates the girlfriend and the closed window somewhat eliminates the thief. The murderer was hoping for a tolerable case against the girlfriend (with a possible secondary scapegoat of the black burglar). If he shoots out the prop holding the window, this helps defeat some of that.
Also, the murderer is intelligent enough to know that trying to shoot the prop could give clues to his method and who did it. Also it takes up time that he sees no purpose in using.