Welcome to the forum!
Glad you joined us, just wish it were better circumstances!
That sounds like something a raccoon would do. Sorry for your loss. You might consider a live trap to reduce the threat. You'll never remove all the raccoons in your area but you can remove the ones that have found your chickens.
I don't have any good numbers for you. I use the electric netting from Premier. Mine plugs into a 110 volt 60 cycle outlet but it goes through a converter. I don't know the volt-amperage output exactly, but the voltmeter reads over 8,000 volts on the fence. The amperage is low enough that it won't kill you if you touch it but you will get a good shock.
It's not a continuous flow of current either but it pulses. I don't know the frequency or duration of the pulse. You might look at Premier's website to try to figure it out.
Mine is netting and I don't think that is what you are talking about. I think you are looking at a couple of electric strands of wire running around the run and coop. You might try going to Tractor Supply and looking at their equipment. You should be able to get some specs off it.
I don't know your knowledge around electricity but you might consider getting a kit. There are some serious legal liability issues if you put out something that can injure or kill a person if they touch it, especially a young kid, whether they should be around or not.