'Blue Bloods' Season 7 spoilers: CBS releases new trailer; Danny is in deep trouble, may face imprisonment for murder [VIDEO]

'Blue Bloods' Star Donnie Wahlberg — Actor Donnie Wahlberg arrives for the International Emmy Awards in New York November 19, 2012. Wahlberg stars as Danny Reagan in the CBS series "Blue Bloods." Reuters/Carlo Allegri

As fans gear up for “Blue Bloods” Season 7, CBS just offered a sneak peek of what’s in store on the pilot episode of the highly popular cop series [watch below].

The trailer centres on Danny Reagan (Donnie Wahlberg), as a ghost from the past comes back to haunt him. He finds himself on the hot seat when the self-defense shooting case of serial killer is re-opened, pinning Danny down for murder. Frank (Tom Selleck) and Erin (Bridget Moynahan) also appears in the preview video. Other “Blue Bloods” characters include Jamie (Will Estes), Henry (Len Cariou), Linda (Amy Carlson), Nicky (Sami Gayle), Det. Maria Baez (Marisa Ramirez) and Officer Eddie Janko (Vanessa Ray).

Spoiler alert! This update contains more "Blue Bloods" Season 7 spoilers. Read on at your own risk.

The opening scene shows Frank and Danny at the cemetery. Danny asks whether Frank has ever regretted being a cop. “I’ve regretted some decisions I’ve made, but never being a cop,” Frank replies. On the next part of the teaser, Danny has nightmares about Thomas Wilder (Louis Cancelmi), the serial he killed last season.

In the trailer, Danny also loses it when he’s being questioned about the case, saying that he meant what he said before: he wanted to kill Wilder. Erin then warns him, “You go into the grand jury talking like that, you’ll go to trial for murder.” Towards the end of the clip, Danny finds himself backed in the corner, as his colleagues accuse him of shooting Wilder for revenge.

Followers of “Blue Bloods” would remember that Thomas, played by “Boardwalk Empire” actor Cancelmi, was a serial killer shot down by Danny in an encounter. This was one of the highlights of “Blue Bloods” Season 6 episode 20 titled “Down the Rabbit Hole.” [READ: “'Blue Bloods' Season 6 Episode 20 spoilers: Danny’s pursuit of a serial killer becomes personal on ‘Down the Rabbit Hole'”]

Earlier this month, CBS revealed new storylines for the upcoming season of “Blue Bloods.” According to spoilers, a new development has surfaced regarding the Wilder case, and it seems to involve an incriminating piece of evidence against Danny. The upcoming season also tackles a controversial car crash and Frank’s struggle with the wife of a slain police officer,

[READ: “‘Blue Bloods' Season 7 update: New storylines centre on Frank's difficult decision; a controversial case comes back to haunt Danny”]

With an average viewership of more than 10 million households per episode, it was no surprise that “Blue Bloods” was renewed for another season. In March, it was announced that CBS has renewed the show, to the delight of its solid fan base.