Hi sarx, and thank you.
I'd asked some questions in response to BeanE's post a couple of pages back, and I have some more if you don't mind.
One of the articles posted cautioned against using shared items. The van belongs to RS, would that preclude them from it for scent? Also, the inside of the van was flooded (they had to wait for it to dry to obtain prints), would that be a reason why they wouldn't use the van for scent? Does it matter if the seats are cloth or leather/vinyl?
How long does scent last (on scene)? What are the effects of water, weather, etc.?
How can an item be contaminated other than smoke or contact? The protocol for obtaining items seems pretty detailed and specific (as posted above). In your experience, when family members are asked to retrieve a scent item, are they given this level of detailed instruction?
Can the shoe that was found beached and ID'd as Shantina's be used for scent?
Using shared items isn't a huge deal if the other person (RS in this case) is there, a scent specific trailing dog will take the scent with that person be told find the other one or may just figure it out on there own and head off to the other scent. In the event the other person isn't there and hasn't been in the area before then it should also be a none issue. When a shared article comes into bad play is when say you are going from the house of Joe and Mary. The shirt has been worn by both that you are using. Mary is the one you are looking for but Joe isn't home. Obviously because they both come and go from this location all the time the dog isn't going to know which one to look for.
I would not want to use seats that have been submerged as a place to swab for a scent article. If there was no other choice then sure, but it would be a last resort.
As far as vinyl/leather etc., you are swabing and wiping off tiny particles that make up the scent (think of micro dandruff), either surface will work. You can even swab the car door with gauze and get your article from that.
How long scent lasts really depends on a lot of factors, heat is your number one enemy. A damp cool environment is ideal. The scent holds to the ground, doesn't disperse and stays around for a long time. How long is long? 2 weeks is the oldest confirmed trail in a real search (in the pacific NW in a nice cool damp forest). We have run trails in practice just over a month old and had success. As time goes by the scent trail disperses and gets smaller. A trail under 3 days old should be easy for dogs in most situations, even in heat, rain, etc. As the trail gets older then external factors start to come into play. 5 days, still quite doable and high probability of being accurate. It starts to decline after that. We've done many a week old trail successful on real searches. We've also had many where the dog went for some time and then would lose the scent. There was another case where there has been a lot of discussion regarding trails as old as 6 months. I spent a lot of time on the phone with a lot of handlers over 3 states and none of us have ever heard or seen anything that would make me comfortable saying that this is something that can be done. I would certainly love to set up some trials for that and see what kind of accuracy we could get with these dogs that are reported to work cold trails. The biology and chemistry of scent just makes me awfully suspect of the liklihood of success. Keep in mind, this REALLY depends on where you live. In the desert you have a much shorter window, if it's damp/humid and cool or moderate the scent will last much longer. Blanket statements can't be made and don't trust them.
How much instruction someone is given really depends on who you're working with. When on mutual aid I've seen LE go with the family to help, I've seen then give a full on lesson of how to do it, I've also seen them just say "go grab something that was theirs".
If the shoe was confirmed to be hers and was not handled by a bunch of people (or if it was and they are still on scene) then yes, it could be used.
Did I get everything?
