Anchored by Jake Tapper, The Lead airs at 4 p.m. ET on CNN.
Journalist Seymour Hersh on controversial news on Syria, plus the latest on winter weather.
Al-Shabaab is a Somali terrorist organization sharing al Qaeda's perverse belief that targeting innocents is the way to fight in the name of Allah.
The group is thought to consist of thousands of fighters, and formally allied itself with al Qaeda in recent years.
Al-Shabaab has proven particularly adept at recruiting American-born jihadis, and the terrorist group claims three of them participated in the attack on an upscale mall in Kenya on Saturday. U.S. officials say they are now combing through evidence to see if that claim is true.
CNN's Jake Tapper reports.