The address of the UPS store is 3217 E Shea Blvd. So they were probably using that address to accept packages. I have an address of 11822 N 31st Street (Phoenix) as the residence. Maybe someone can check that out. This address is listed as the residence of Larry L Young and Mary Buber. Maybe they were the married couple and Mark was Mary's brother? In a Google obituary search, I found a very short notice that Larry L Young was born Jan 5 1936 and died Jun 1 2018.