Mark Leonard Bridger was born on November 6, 1965, at the War Memorial Hospital in Carshalton, Surrey. He was the second of three children in his family. His father, Graham Bridger, worked as a policeman, and his mother, Pamela, took care of the household. He had an older sister and a younger brother. The family lived in a semi-detached house in Wallington, Surrey.

When it came to his education, Mark attended John Ruskin High School in Croydon. He completed his studies with seven CSE qualifications, which are the equivalent of high school exams. After finishing school, Mark had a series of small jobs. He worked in different fields, including as an abattoir worker, hotel porter, fireman, lifeguard, mechanic, and welder.

On the evening of October 1, 2012, April Jones was last seen near her home in Machynlleth, Wales. After attending swimming lessons, she went outside to play with a friend. Her parents gave permission for her to stay out for a while. Approximately twenty minutes after she left, her mother began looking for her when she realized April was missing.

The local police were called, and they quickly started a massive search operation. Eyewitnesses reported seeing April get into a grey van shortly after she disappeared. This led the police to focus their attention on Mark Bridger, a local man who matched the description given. He was arrested on October 2, less than a day after April was reported missing.

As the investigation continued, the case was classified as a murder inquiry on October 5, even though April’s body had not been found. Bridger was charged with abduction, murder, and perverting the course of justice on October 6. He pleaded not guilty to the murder charge during court proceedings but acknowledged he was "probably responsible" for her death.

Bridger's trial began on April 29, 2013. In the trial, evidence included human bone fragments found in his fireplace and blood that matched April's DNA. The court determined that the injuries found were fatal. Finally, on May 30, 2013, Bridger was found guilty of abduction, murder, and perverting the course of justice. He was sentenced to life imprisonment with a whole-life order.

After the verdict, Bridger claimed to have disposed of April's body in a river. However, police expressed doubt about his claims, suggesting he might have scattered her remains nearby. Despite the efforts of authorities, April’s body was never recovered, although some bone fragments were found in his home. Following Bridger's arrest, police also discovered a large collection of child pornography on his computer.

In the years that followed, Bridger became a target of violence in prison and was attacked by an inmate. He also attempted to appeal his life sentence but dropped the appeal shortly before it was due to be heard. The tragic case led to significant changes in how search engines handled child abuse images. The cottage where Bridger lived was eventually bought by the Welsh Government and demolished in 2014.