Co-owner Wants To Add Someone To The Deed

[Zana Blue]

My friend is in a pickle...he is co-owner of a small house and both are listed on the deed...the other owner is in ICU but in the meantime someone he met online who was in jail got released and has decided to move into the house while that person is in the hospital ! The new person wants to be added to the deed...I told my friend he can not be added without both co-owners agreeing and getting it notarized and recorded...I hope I am right and of course he should consult an attorney but I fear there will be some shenanigans pulled to get the new guy on the deed yikes !