Soft target / Stephen Hunter.

Enhanced descriptions from Syndetics:

New York Timesbestselling author Stephen Hunter is back with a breakneck thriller brimming with his trademark action and masterful plotting, as ex-Marine sniper Ray Cruz confronts a group of murderous terrorists who've laid siege to the Mall of America.

It starts out as a simple shopping trip with his fiancÉe. But suddenly, retired marine sergeant Ray Cruz, whom we met in Hunter's last bestseller,Dead Zero, is in the middle of the softest target of all, a huge emporium outside Minneapolis where a self-styled "Mumbai Brigade" has come to bring massive death to the heartland.

Hunter flashes over the events as if in real time: the assembly of the killer team composed of terrorists from one of the world's hellholes, but led by a nihilistic insider who knows the mall backwards and forwards and has taken over the security software as well as the vast building and 1,000 hostages; the politics of SWAT as officials argue over tactics outside while the killing goes on inside; the panic in the halls of the death zone, as hostages are herded to an amusement park. As the clock ticks on, the terrorists begin to execute their captives. But they don't know Ray Cruz is in the building…

With a nail-biting premise and singular hero who exhibits heart as well as guts,Soft Targetis everything a thriller should be--timely, shocking, and full of high-stakes drama.