sad to hear about your bro loss of bike.
i had one of my favorite bikes stolen from a double locked (door/cable) shed. they were out of sight out of existance to theft, i thought.
i still keep my bikes inside, locked. if someone really wants to get the bike, they will. the locks are a deterent to help keep the honest people honest. (my own rationalization)
to keep history from repeating, could your bro bring the next (or hopefully recovered) bicycle into the place he is acting at? (out of sight/existance)