The ITV four-parter series concludes tonight and viewers will be hoping the killer is finally exposed.
However when Lee was interviewed by Eamonn Holmes and Ruth Langsford, he gave away a big clue.
Although it looked as though David had been ruled out as a suspect due to development in the case in last night’s episode, that may not be the case at all.
The 42-year-old confessed: “His temper has been borne from being inside and wanting to get out there and speak out.
“Being back in a society that just doesn’t want him there, you think you’re feeling safe with him and then…”
Have viewers been lulled into a false sense of security and led to believe that David is innocent?
Eamonn also pointed to another attribute of David that could have marked him out as a murderer from the beginning.
The Irishman thought the beard the actor sported for the role indicated he was the killer.
Eamonn speculated: “It makes you more likely to be the killer, I think.”
“Maybe,” Lee laughed.
Eamonn continued: “I think out makes him more sinister.”
“If you look at the serial killers, they’ve all got beards,” Lee joked.
Ruth and Eamonn speculated whether there would be a definite end for the series or if it would be left on a cliffhanger to make way for a second season.
Lee confirmed “It’s got an ending, it will resolve.
“You will find out what’s gone on.”
Along with David, the main suspects for the murder include his sister-in-law Alice Moffatt (played by Hermione Norris) as well as his brother Phil Collins (Daniel Ryan).
Lee went to say how they all had reasons to kill Tara and that even he had tried to guess when reading the script.
He said: “They’ve all got little reasons, something to gain, something to hide. They’ve all got secrets and lies.
“People love to guess, even I did when I was reading it, but I skipped to the end.”
Innocent concludes tonight at 9pm on ITV.