MacBook password help - deceased relative

Hi,

I am trying to gain access to my cousins two MacBooks. He was murdered a year and a half ago and my aunt just got all of his electronics back from the police dept.

I have access to his iPad and can see his iCloud with the MacBook under my devices and what not but Everytime I try and reset the password on the computer it tells me it can’t connect to iCloud. I can’t use his phone number as it’s already been given to someone else. Also his appleid email was his work email which I am sure is no longer available.

Is there any work around to fix this? I’d love to get into the computer so my aunt can save the pictures of him and his kids.