It was a distinctive smell, similar to vinegar, seeping from the new-built home at the top of the hill that prompted a resident in Tijuana’s Lomas del Valle neighbourhood to make an anonymous call to the police in October last year.
A few nights later three patrol cars were seen heading up the potholed road to the elevated dusty area, a 50-minute drive and a world away from the souvenir stores and tequila bars of Mexico’s main northern border city. Their target was a squat, grey building that seemed in a permanently stalled state of construction.
