Security guard fatally shoots gunman who killed third man in South Shore

A store security guard fatally shot a gunman who shot and killed another man Thursday afternoon near a busy intersection in the South Shore neighborhood, according to Chicago police.

The daylight shooting began as an argument between the 25-year-old gunman and a 22-year-old man around 2:50 p.m. in the 7100 block of South Jeffery Boulevard, police said in a media notification.