Erin Reagan (Bridget Moynahan) gets an unexpected pang of guilt after winning a case in the next episode of "Blue Bloods" season 6.

In an intense teaser for the upcoming episode titled "Fresh Start," one of Erin's clients whom she managed to set free is being accused of killing a cop. This made her feel responsible for the death of the fallen officer.

The teaser also shows that Erin exerted extra effort to comfort the loved ones of the fallen officer. But as she apologizes, one of the officer's relatives gives her a very hard slap in the face.

The episode's guests are Kyle Paul as Officer Kenneth Nelson, Adriana Demeo as Laura Nelson, Scott Aiello as Officer Abrams, Leo Minaya as Javier Fernandez, Billy Smith as Sgt. Rutkowski, and Liza Bennett as Mrs. Gibson. It will air on Friday, Feb. 19.

Meanwhile, Erin's father Frank (Tom Selleck) will face the very outspoken City Council Speaker Regina Thomas in the episode titled "Help Me Help You."

Thomas, portrayed by the Oscar Award-winning actress Whoopi Goldberg, will let the public know that she is not in favor of the "broken window policy" that is being implemented by the New York Police Department under Frank's leadership.

The episode will also reveal that Linda (Amy Carlson) will ask her husband Danny (Donnie Wahlberg) and his partner Maria Baez (Marisa Ramirez) to help one of her colleagues who is being bothered by her angry ex-husband. While the extent of the trouble is not revealed in the synopsis for the episode, needing the police assistance means that the life of Linda's co-worker could be in grave danger.

Episode 16 airs on Feb. 26 on CBS.