Parkin later told police: “She was so sad when she found out what I really am.

“I should have killed myself. What is wrong with me? There is something wrong with me.”

Police later found search terms on his computer such as “Cambodia child abuse”, “teacher sexually assaulted” and “teacher viewing porn”.

They also found three indecent videos on his phone.

Detectives found Mrs Parkin’s computer had accessed pages such as “what to do if you don’t feel loved enough in your relationship”, “top five signs your husband is demanding and controlling” and “fight for your marriage when your husband is emotionally distant from you”.

The court heard how the mother-of-two’s murder devastated her pupils at West Boldon Primary School.

In a statement to the court, her mother Patricia Oxley said: “Our lives were shattered forever, I cannot find the words to fully explain how I feel.

“‘Anger, grief and despair’ are simply inadequate.”

Paul Greaney QC, defending, said Parkin had pleaded guilty at the first opportunity to murder, attempted murder and making indecent images of a child.

He insisted on behalf of his client that Parkin had loved his wife, despite the horrific nature of the crime.

Judge Paul Sloan QC jailed Parkin for life with a minimum term of 23 years before he can be considered for parole and imposed a Sexual Harm Prevention Order.