28 people, including 20 children, are dead. (Google Maps)

20-year-old Adam Lanza allegedly walked into Sandy Hook Elementary School and opened fire after arguing with the school's principal.

Lanza targeted administrators and children before turning the gun on himself. 

Earlier, media outlets had identified 24-year-old Ryan Lanza, Adam's brother, as the suspect. 

Universal Uclick cartoonist Matt Bors took a screenshot of Ryan's reaction to the media blitz.

Ryan Lanza is currently being questioned by the police.

Among the dead: Nancy Lanza, the suspect's mother, who worked at the elementary school as a kindergarten teacher. The suspect's girlfriend and a friend of the suspect are reportedly missing.

The school shooting is the second deadliest school shooting in U.S. History. It occured just days after a gunman killed two people in an Oregon shopping mall. The Nation notes that at least 16 high-profile mass shootings have occured since the start of 2012.

Reach reporter Aaron Liu here.