When Matty was killed five years prior to the start of the series, teacher Sally Wright (Katherine Kelly) was charged and sent to prison for the crime, with many believing that she had an affair with her student.
After Sally is found not guilty in a re-trial, new evidence is unearthed in the case, including the fact that Matty’s dad John Taylor (Andrew Tiernan) isn’t actually his biological father.
In the latest instalment of the series, it’s revealed that Karen’s daughter (Amy-Leigh Hickman) was bullied by Matty, resulting in her mother – who was Matty’s social worker – stepping in.
However, as Karen hides the fact that she and Matty had a heated exchange on the day of his death, what else is she not being honest about?
Is Karen hiding more lies?
Episode three of Innocent lays bare the extent of Karen’s many lies.
Not only does she lie to the police about the fact that she and Matty had an altercation on the day he died, but it’s also revealed that she lied to the hospital when her daughter, Beth, suffered an almost fatal overdose.
When Karen tells the police that she didn’t see Matty on the day of his death, she doesn’t realise that her fiancé Sam Wright (Jamie Bamber) already went behind her back to tell them the truth.
With the police carrying out tests to see whether fibres from Karen can be found on Matty’s clothing, has she found herself in hot water?
What was Matty’s relationship with biological father?
While John Taylor and his wife Maria Taylor (Lucy Black) claimed Matty’s biological father was a one night stand, the man is identified in episode three as Gary Walker.
Gary and John both share different accounts with the police regarding Matty’s meeting with his biological father, with Gary claiming that he wanted to help support Matty and John stating the opposite.
While Gary does seem like a suspect worth keeping an eye on, by the end of the episode, it’s confirmed that his alibi does check out.
However, this still doesn’t explain why no one can seem to agree on what his and Matty’s relationship was really like.
Does Sally’s ex-husband Sam have a secret?
When being questioned by the police, Sam tells them that on the day that Matty died, he had an appointment with Aaron Holmes, who he was working with as part of his role as a probation officer.
Aaron confirms this alibi when the police come to see him.
However, at the end of the episode, he calls Sam, telling him that they need to have a chat.
Is there more to Sam’s supposed alibi than viewers have been told so far?
Innocent returns tomorrow at 9pm on ITV.
Got a story?
If you’ve got a celebrity story, video or pictures get in touch with the Metro.co.uk entertainment team by emailing us firstname.lastname@example.org, calling 020 3615 2145 or by visiting our Submit Stuff page we’d love to hear from you.
MORE : Where is ITV’s crime drama Innocent filmed?
MORE : ITV’s Innocent: What else has Katherine Kelly been in?