At some point during the investigation days in each episode, the killer would leave some form of message showcasing two locations, usually accompanied by the taunting words 'coming out to play?'.

Jay was wearing the same shirt when Sam, Nick, and Christine saw him at the morgue the day after Catherine was attacked and he said then that he hadn't changed for twenty-four hours.

The Chief asked if the phone had been answered to which Nick denied having done so; this initially went unnoticed but the truth was discovered on the second day after a review of the teams work.

The investigators were to visit Dean at his home address but upon their arrival the previously missing wedding car pulled out of the drive way at high speed.

Sarita coordinated a more systematic search of the area which led to Ruairi finding Dean's missing video camera.

Lead Investigator: Nick The clue was discovered to be a scribbled note on an envelope that was perceived to be a meeting that was arranged to take place the following day.

The Chief sends out his special team to recover the tracker and it is shown to provide evidence that the car was driven to the Sluice Pond in the early hours of the morning before returning.

Forensics discovered that there were two prints, one came from Jay Wilmington, the owner of the boat and the second belonged to Catherine Prior Killer’s Calling Card: On the morning of Day 2.

The investigators spot the vital evidence, which is a red coat hanging in a tree that contains an invitation to the wedding addressed to Tina Wells.

Due to the investigators questioning Jays relationship with Catherine in front of Goldie, she decided to leave, resulting in Andrew attempting to catch up with her to enable them to interview her.

The investigators are able to clear Vanessa as she has an alibi for the time of the murder but it is discussed that she has also attempted to provide a cover story for Dean.

He advised to refuse to answer any general questions and focus only on using the press conference to appeal for information on the last known movements of Catherine prior to her murder.

Lead Investigator: Melanie Tina tells them about a secret that Catherine had divulged to her two weeks before her murder involving the Wilmington House and 'Alice's Room' and something contained within it which will 'change everything'.

Meryl asks about the phone call and Tina admits that she has been receiving them at home and on her mobile before insisting that she is allowed to leave as she needs to carry on with what she was doing.

Killer’s Calling Card: While digging the grave at the church graveyard, Meryl and Nick found a photo album, containing a picture of the Wilmington’s in the 1930’s and three Polaroids with the locations “The Hospital” and “The Fortress” on them.

They are then able to use the box of family tree information collected from Tina and the knowledge about Trevor's mother to establish that the dead baby is likely to have been Dorothy's and not Felicity's.

During the night of Day 1 the Chief is told that there has been a disturbance at a local farm and a search team has been sent out with sniffer dogs and a piece of Tina's clothing.

The Lead Investigator, Ruairi, informs them that Catherine's phone records have arrived and Trevor called her minutes before she was murdered.

Andrew spots the visual clue, it is the same picture that was discovered in a photo album that had been buried by the killer for the investigators to find previously.

While being questioned by the investigators George has a friend, Rodney 'Rod' Lewis, stop by and show off the back of the daily paper which contains a photo of Rod holding a large fish.

Killer’s Calling Card: As stated at the end of Andrew and Richard’s Day 1 Investigation, while stranded due to a high tide.

The duo found the Polaroids on a fence with the sign “Coming out to Play” on it when a flare was fired off with the locations “The Quarry” and “The Derelict Barn” on them.

Upon putting the letter back together, it was discovered to have been written by Charles Wilmington for his son Tony and contained the revelation of the existence of the necklace.

The letter reveals that Jay has heard the contents of the tape before his wedding was due to take place, and the person who enabled him to hear it was Catherine herself.

The investigators realize it may clear Goldie or Jay, or potentially Trevor if he had access to the account but they would need CCTV to identify who made the withdrawal as the pin number and card could have been used by anyone they trusted.

Goldie also tells the investigators that she did not reveal what actually happened on the morning of the murder when they first asked about her movements that day because she didn't want to implicate Jay as being the killer.

[2] The Kelvedon Hatch Secret Nuclear Bunker was also used in the series, where Andrew Weaver and Nick Sykes went to the Operational Zone and Living Quarters respectively during the second-to-last Killer's Game.

Andrew was sent to the Yacht Club, where Trevor was last seen, and was "invited" To the final killers game at the Construction warehouse, where he found Bob Taylor at the end, who proclaimed him as the winner of the £25,000 grand prize.

Using Sky, Cable or Freeview, viewers could watch additional parts of the show using BBCi's digital interactive features.

One feature entitled Blackwater TV was based around reviewing the case and showing mock television news reports.