My brother in law got out of prison in 2018 and was living with me till he died in 2018 in my home. Can i claim him as a dependent?

I'm sorry for your loss.

Yes - you can claim your brother-in-law as a dependent as a "qualifying relative" if he meets these requirements:

1. Not a qualifying child - Since he was your brother-in-law, he could not be a qualifying child.
2. Member of household or relationship test – He is related to you
   
3. Gross income test - To meet this test, a person's gross income for the year must be less than $4,150.  Gross income is all income in the form of money, property, and services that isn't exempt from tax.
4. Support test - To meet this test, you generally must provide more than half of a person's total support during the calendar year.  You figure whether you have provided more than half of a person's total support by comparing the amount you contributed to that person's support with the entire amount of support that person received from all sources. This includes support the person provided from his or her own funds.