Attorneys for Walmart and Wackenhut argued Garrett, 44, never did anything to arouse suspicion or otherwise cause them to compel him to leave before he punched Born and robbed him. Garrett, who is 6-feet 3 inches tall and weighed 250 pounds at the time of the incident, was on store property for about 12 minutes before he attacked Born. Attorneys said he was not loitering or acting erratic.[lasvegasinfonewspaper.com]

It's hard to tell with out studying the transcripts, but based on the story, it's hard to imagine any way they could have forseen or prevented the attack ...