The Sentinel - Season 4

20/20 continues to combine hard-hitting investigative reports, newsmaker interviews and compelling human interest and feature stories.

An exciting new reality show that, in these trying economic times, gives budding entrepreneurs a chance to make their dreams come true and become successful - and possibly wealthy - business people. But the entrepreneurs must first try to convince five tough, multi-millionaire tycoons to part with their own hard-earned cash and give them the funding they need to jumpstart their business ideas.

Enter the Sharks of Shark Tank, who lifted themselves up by their bootstraps to make their own entrepreneurial dreams come true and turned their ideas into empires. The five Sharks of this ruthless panel are real estate mogul Barbara Corcoran, "infomercial" industry pioneer Kevin Harrington, technology innovator Robert Herjavec, fashion icon Daymond John and financial expert Kevin O'Leary.

In this workplace comedy, a group of dedicated, passionate teachers — and a slightly tone-deaf principal — are brought together in a Philadelphia public school where, despite the odds stacked against them, they are determined to help their students succeed in life. Though these incredible public servants may be outnumbered and underfunded, they love what they do — even if they don't love the school district's less-than-stellar attitude toward educating children.

In Will Trent Special Agent Will Trent of the Georgia Bureau of Investigations was abandoned at birth and endured a harsh coming-of-age in Atlanta's overwhelmed foster care system. But now, determined to use his unique point of view to make sure no one is abandoned like he was, Trent has the highest clearance rate in the GBI.

The Rookie is inspired by a true story. John Nolan is the oldest rookie in the LAPD. At an age where most are at the peak of their career, Nolan cast aside his comfortable, small town life and moved to L.A. to pursue his dream of being a cop. Now, surrounded by rookies twenty years his junior, Nolan must navigate the dangerous, humorous and unpredictable world of a "young" cop, determined to make his second shot at life count.