Online neighbor dread is reflected in Arbery’s Facebook posts.

Months before Ahmaud Arbery was slain, gunman Travis McMichael responded to a Facebook post about a suspected vehicle burglary in his Georgia neighborhood with a simple, terrifying message: “Raise your arms.”

Like many online groups in the United States centered on geographical areas, the article he commented on was wedged between chats about lost pets and water service outage.

However, in the year leading up to Arbery’s death, residents in McMichael’s subdivision’s Facebook group described a neighborhood that was becoming increasingly tense over minor incidents, with residents trading suspicions, keeping children inside, and becoming willing to take matters into their own hands.

Such online neighborhood forums in the United States have a worrying propensity to shift from benign communal chitchat to neurotic hyper vigilance when suspicion is the topic of conversation, especially at a time when racism, criminal justice, and the role of technology are all being re-examined.

“It makes individuals feel more nervous, on edge, or hypersensitive.” But, according to media psychologist Pamela Rutledge, “it also makes people more skeptical of someone who isn’t like them” in a number of ways. “It’s sort of stacking the kindling, as it were, because then people are looking for anything to go wrong.”

The murder trial for McMichael and two other white males charged in the slaying of Arbery, whose death became part of a bigger reflection on racial unfairness in the criminal justice system, is slated to conclude Monday.

After noticing Arbery, a 25-year-old Black man, rushing through their neighborhood outside of the Georgia port city of Brunswick in February 2020, father and son Greg and Travis McMichael grabbed pistols and chased him down in a pickup truck. Travis McMichael shot Arbery as he threw punches and grabbed for the shotgun, according to William “Roddie” Bryan, who joined the chase in his own truck.