The Lindenberg case which I am familiar with. The forensic scientist that examined the ladder claimed notoriety for finding out where the ladder was made. The ladder was not on site though. Whoever took the child brought the ladder to the house if memory serves me right. Still a mystery.

The ladder was left behind broken into 3 parts in the bushes because it didn't matter. The ladder was simply out of sight so the kidnapper could have extra time to get away with the Lindbergh baby. Leavign the adder visible would have made it more likely to know somethign was wrong and discover the baby was missing sooner. In this case the ladder would need to be removed entirely since the whole purpose would have been to leave from a second story window without appearing to have left through it. Unless there was absolutely no possible alternative who would go through the work involved?
PS Yes supposedly the wood was tied to a garage where it had been made from the rafters. The man staying in that house (Hauptmann) also had around $15,000 of the ransom money in it. The defense suggested he was framed by the real killer and a number of people still wonder if he was framed or not.
Someone in the NY area spent several thousand dollars and it actually took quite a while to track the spending to Hauptmann. He had no good excuse for having the money.
A lot of the money never turned up which feeds into the conspiracy theories. Either 1) he had an accomplice(s) who decided to destroy the money after they saw it lead to Hauptmann being caught, 2) he hid it somewhere that to this day no one has discovered, or 3) someone who owned the house subsequently found his stash but never revealed it (The money is no longer legal tender so at this point is only a collectible so unless into numismatics is won't matter and a collector might even be scared to disclose the truth out of dear of the certificates being taken away).
I can't see someone giving him $20,000 so he gets caught, spend nothing theselves and just toss the rest of the money away.