HARTFORD, Conn. (AP) — Newtown school shooter Adam Lanza heard the message loud and clear when gun-maker Remington Arms marketed an AR-15-style rifle as an overpowering weapon favored by elite military forces, a lawyer for relatives of some victims of the massacre told the Connecticut Supreme Court on Tuesday.

Lanza, who killed 20 first-graders and six educators with a Bushmaster XM15-E2S on Dec. 14, 2012, was obsessed with violent video games and idolized the Army Rangers, attorney Joshua Koskoff said.

Koskoff asked the high court to reinstate a wrongful death lawsuit against Madison, North C...