Identifying a suspect blindly off of a check is highly unlikely. Normally prints are used to positively ID a suspect you have already identified as likely.

Actually, the investigator is correct, the victim/endorser is the entity that takes the loss. Check cashers charge payees to cover their losses and make some profit. Banks usually won't cash checks unless you are an account holder. If you have enough employees to set up accounts tied to debit cards, that is definitely a better way to go. Most large employers have been doing that for years. Small businesses make that difficult because you can't cover the administrative costs to make it worthwhile. There are some payroll companies that will could probably help you. They are able to set up accounts with several smaller businesses to spread the cost out. It still will cost you money, but it may be worth it to avoid having your paper checks floating around.

Nothing is counterfeit proof. If the investigator and cops can't identify the groups responsible, you will be forced to keep changing accounts or find another way of paying your employees.

Criminals can be ingenious and they are definitely persistent.