Private Citizen Proving Ability to Pay Reward for Crime Information

[Toaster]

If a private citizen wants to give a reward for information leading to a criminal that has done wrong to said citizen (like "Help me find that guy who murdered my kids" or "Help me find that guy who backed into my Honda and didn't give me real insurance information"), how would they go about proving to those wishing to give information that they would indeed give them the reward?

This is totally hypothetical, I don't even have a Honda.

I am guessing they would set up the money in an escrow account or to some third party, and get a legal contract with notarization with stipulations on proving the information is real and valuable before payment, but my Googling is terrible when I am tired, and nothing has come out of it.

Are there cases where this has been done before?

[According to Pliny]

I think tipsters are fairly gullible. They will trust you. The problem is usually how to assure them annonymity until the perp is in custody. The way newspaper tipster columns work is that they have to tear a corner off their tip, and write some long number on the tip page they mail in, and the corner that they keep until it's time to collect.

[According to Pliny]

As to getting the word out, a person would just call the cops, the local paper, and news outlets with the info.
They know the drill.

[Toaster]

That's an interesting way, with the tipster columns. Do they normally have to wait until the subject in question is apprehended & processed-with-a-guilty-outcome to get the reward? If so, what happens if the subject is apprehended & processed-with-a-not-guilty-outcome?

[Moirai]

Huh. I know a guy who offered a reward for information once... but he is a major sports figure so everybody knew he had the money!