"Blue Bloods" season 6 ended with Danny (Donnie Wahlberg) catching and killing serial killer Thomas Wilder (Louis Cancelmi), claiming it was in self-defense. When season 7 returns, this claim is going to be put to the test and the rest of the precinct will be dealing with two other mind-cases of their own.

As stated in a report from Spoiler TV, Danny's claim will be argued against by Michael Lewis (guest star Michael Imperioli) who brings in evidence from the Attorney General's office, evidence that could prove Wilder's death was not just in self-defense and could have been a meditated murder.

Fans will recall that Danny's encounter with Wilder was during the final few episodes of season 6 but there were two more episodes that followed, making it appear as if his fight with Wilder had come to a close. As the plot details reveal, Danny still has a lot of trouble related with Wilder that he has to deal with.

While Danny deals with the charges and the ramifications of the death of Wilder, Frank (Tom Selleck) will be handling his own conundrum when the wife of a slain police officer, Grace Edwards (guest star Lori Loughlin), asks him to convince her son to not sign up and join the police force.

Jamie (Will Estes) and Eddie (Vanessa Ray), on the other hand, will have their hands full when they respond to an "explosive car crash" only to find out that it involves a drunk driver that turns out to be a public figure. How they will handle a delicate situation will be the main focus of their segment in the episode.

Season 7 will see Frank back in position as head of the precinct and his family given that actor Tom Selleck has been confirmed to return, proving that Frank's resignation submitted during the season 6 finale had been turned down by the mayor, effectively keeping him on the job.

"Blue Bloods" season 7 premieres this Sept. 23.