Things get personal for Erin (Sophia Bush) when her mother gets involved in a murder case, in the upcoming finale of "Chicago P.D." season 4.

Titled "Fork in the Road," this week's episode will see Erin try to navigate the Chicago Police Department politics after Bunny Fletcher's (guest star Markie Post) is implicated in a murder case. According to the official synopsis, Erin receives a panicked call from Bunny, saying her boyfriend has just been shot. Erin finds a proper way to approach the situation now that her mother is a suspect in the murder.

New leads surface when a group of high school students get overdosed and the drugs in question are traced back to Bunny's situation. Aside from her mother's problems, Erin has to answer to the review board regarding her actions.

The teaser shows Erin facing the review board as they tell her the consequences of her actions. One of the board members says she will likely be charged with aggravated assault. It turns out that prior to the victim's death, Erin shoved a gun at his throat because they had a heated argument. "I do not regret what I did," Erin tells the members of the board. Hank (Jason Beghe) appears to be confronting someone about Erin's situation and says, "The second you put her in jeopardy, I'm coming after you."

Last week, NBC officially renewed "Chicago P.D." for a fifth season. Other shows in the franchise including "Chicago Med" and "Chicago Fire" were also picked up, but the network has yet to decide on the future of rookie drama "Chicago Justice." 

The cop drama continues to be one of NBC's best performers in the 18–49 demo, with an average rating of 2.4 and 10.1 million viewers in the current season. "Chicago P.D." went through a lot of changes this season when series regular Jon Seda moved to "Chicago Justice" and co-creator/showrunner Matt Olmstead left the series for an overall deal with ABC Studios.

The "Chicago P.D." season 4 finale airs Wednesday, May 17, at 10 p.m. EDT on NBC.