I have some questions...
Mass-murders are extremely uncommon. They are only common on the TV. I find the following (Sweden):http://sv.wikipedia.org/wiki/Lista_%C3%B6ver_brott_i_Sverige
* Anders Lindbäck – Arsenik i nattvardsvinet dödade tre äldre personer 1865.
(Thee killed, poison)
* Massmordet ombord på ångaren Prins Carl – Mord på fem personer år 1900.
(Five killed and eight injured)
* Lasermannen – 11 personer skjutna varav 1 dog under 10 attentat, Stockholmsområdet 1991 - 1992.
(Eleven shot on different occasions resulting in one killed)
* Mattias Flink - Natten den 11 juni 1994 sköt den 24-årige fänriken Mattias Flink ihjäl sju personer i centrala Falun.
* Malexandermorden – Mord på två poliser 1999
* Arbogamorden – Morden på två barn i Arboga som inträffade i mars 2008.
To qualify as a mass-murder (in Sweden, source sv.wikipedia.org) you have to kill more than three people on a single occasion. This is unusual to a degree that crime statistics find only two occasions during last 146 years (in Sweden, by wiki).
It is difficult to shoot. It is not as on television. It is difficult to hit somebody. It take skills, and a lot of practice. Most hunting is shooting on non-moving targets, by waking slowly towards the animal. Even if the animals are driven towards the shooter, shooting of moose take place when the moose have stopped, and usually from an elevated position. Can a skilled hunter please help here?
... and usually using a scope!
Girls on a summer camp can run appallingly fast in a forest, and will run out of effective shooting distance within four seconds maximum. This don't allow for much shooting. If someone spot the gunman in a forest, in the distance, it is likely that the entire area can be emptied, with all people running well out of effective shooting distance, and not a single one killed. You can't hit running people if there are not extremely close to you, within a handful of meters.
If a gunman/hostage taker opens a car door, and point a big gun into your face, the odds are as follows (source FBI??): If you run away, there is about a 50% chance that he don't shoot. If he shoots, there is a 50% chance that he don't hit you. If he do hit you, there is a 50% chance that you die. (If you enter the car you will most certainly die.) (This is for a talking-distance start, where the gunman is in your face.)
It is possible to kill at large distances, some 4km if a rifle is used and possibly 500m if a pistol is used (a machine gun bullet killed by accident from 5-6 km), but it don't work like that if you intend to aim for your target. If you can fool people to come forward and show themselves, you would likely have a good chance to kill about two of them. You can't hit the rest even if you have an unobstructed view; they will have time to run too far away. You must figure out where a singe one is running, aim at a point ahead of him, and squeeze the trigger gently, and accurately timed, when the target run through your aim-point. (How much ammo did this Rambo stuff in the back-pack initially?
We see that The Loone Assassin will be tempted to shoot at random into, or towards a crowd, or towards people, more or less at random. This is, of course, lethal. But the estimated Injury to Kill ratio should be rather high. People also refuse to die properly when shot. Some injured are expected to go screaming. The amount of screaming, that can be produced before death, will likely be told by at least some witnesses. Some will remember that something did hit them, but will not associate this with a gun wound. Some witnesses will likely tell when they have found a wound on a friend, that himself did not recognise this as being serious.
Young people do not see their cell phones as being strange or difficult to operate. If shot at, and hunted through a forest in full panic, they will switch the phone to silent, and they will call the emergency centre. All such phone calls are taped, and the timing accuracy is within one second. If someone see the gun-man, a long intelligible and detailed voice account is to be expected, and there should also be simultaneous calls to allow tracking of the gunman over the island. You should basically have 200+ simultaneous calls, all on tape. Yes, they do have this capacity at the emergency centre!
You don't convert fertilizer into a bomb by breakfast either. The chemistry may involve grinding of the fertiliser into a dust like powder, mixing with another substance like some kind of fuel, mixing these in exact proportions by using a professional scale. Home-made bombs also, usually, have the draw-back of burning slow, too slow to burn the entire mass; most part of the bomb is simply scattered. It is recommended to load the bomb (build it) inside a high-pressure container, with the advantage that the container will be real nasty when it is destroyed and blown all over the place. You must also test-shoot your product multiple times. To fire your fertilizer bomb ordinary explosives must be used, as the pressure wave needed is very difficult to obtain using home-made means.
(picture of preferred implementation. Weld the hole at the back, and stand well clear when it go off
So I expect the following:
- A small chemistry lab, including industry size mixers and grinders.
- The existence of a suitable test-site.
- Damaged trees, and residue of explosives on the test-site
- A high pressure container found on the target site, cut to a handful pieces by the explosive.
- Welding equipment; for set-up of the lab, and also for manufacturing or modification of the pressure container.
- A Loone-Nutter, with a profile matching the use of this equipment.
Yes , and:
- Long, detailed, and authentic accounts from the shooting on the island, by taped SOS-calls.
- A massive amount of injured people, especially when compared to the number of deaths.
- An even higher amount of missed shots, each with a picture of a hole in a tree; the bullet drilled out. Bullet holes all over the place.
- A Loone-Nutter, with a profile matching an experienced hunter or competition shooter; possibly experienced shooting on moving targets.
Note that the Loone Gunman-theory have several advantages when compared to a scenario with several criminals; as if they are several, you can also track communication between the participants, and it often gets very complicated.
[Addition]No, this don't make sense. If you DO manufacture explosives, and INTEND to kill as many on the summer camp as possible, simply series-produce the test-bomb, and attach some means so it can work as a trap or a mine. Put these out in the forest in advance; this will take an hour or so, and then simply shoot in the air to scare people into running. Let the explosives do most of the nasty job.