Help !!!! My step-grandma won’t give us our checks!!!!

My grandfather passed in 2019 and his death was….. suspicious. Like we didn’t even know he was sick much less dying until we went to visit him in Louisiana and saw him on his death bed. We thought this man had bad gout and needed a pacemaker. The state he was in reminded me of the young people that got put into the old people’s bodies at the end of Skeleton Key.

So after he died we had the funeral. The whole time his wife is acting funny she wanted nothing to do with my mom and her siblings, didn’t come to the repast, didn’t want his ashes (cause she had him cremated even though he had a whole ass tomb he wanted to be put in), and outright refused to take the big portrait that was done for the funeral and basically disappeared.

Well about two months ago my mom got a call from this guy that had been staying with my grandfather and step-grandma and he basically confessed to a ton of bull shit and shenanigans. They, ole dude and step-grandma, had got crooked lawyers to change wills and bank accounts and other documents so that when he passed everything would go to her.

While I know the whole crooked lawyers and falsifying documentation is something for the legal system to handle supposedly she is holding on to life insurance payout checks that rightfully belong to my mom and her siblings. How would they go about claiming them or even checking to see if they exist?