Who Was Carl Langdell, The Plenty Of Fish Killer?

In December 2015, 26-year-old Carl Langdell and 23-year-old Katie Locke met through a dating app called Plenty of Fish. Although the app was designed for people to make romantic connections, the connection between Langdell and Locke would have devastating — and ultimately deadly — consequences.

As reported by the Daily Mail, Locke attended Southampton University, where she earned a degree in history and politics. When she met Langdell, she was working as a history teacher at Cardinal Pole School in Hackney, East London, England. In addition to teaching, she enjoyed water sports and volunteering to help underprivileged children. Per the Daily Mail, Locke's father, Bill, said his daughter "was self-confident and fearless and an energetic and beautiful person."

Langdell introduced himself to Locke as an attorney who owned his own law firm. The New York Post reports that Langdell's LinkedIn profile indicated he was attending BPP University Law School. The profile also stated he was actively involved in several organizations at Cardiff University, where he served as social secretary for the Athletics Union and captain of the golf team.

According to the New York Post, Langdell and Locke communicated via the internet and telephone for two weeks before they agreed to meet in person on December 23. As reported by The U.S. Sun, they met at the Trafik bar in Shoreditch, East London, where they had drinks and talked into the early morning hours of December 24. At some point during the evening, Locke sent a text message to her friend saying that she was having a good time.

The New York Post reports that Carl Langdell and Katie Locke left the Trafik bar in the early morning hours of December 24, 2015, and took a taxi to Theobolds Park Hotel in Waltham Cross, Hertfordshire. According to witness reports, Langdell and Locke checked into the hotel at approximately 3:30 am. Per The U.S. Sun, the hotel's receptionist said Langdell and Locke both appeared to be "very intoxicated" when they checked in. She also noted that Langdell was having trouble walking and Locke seemed to be holding him up as they made their way down the hallway toward their room.

Shortly after settling into their room, Locke called the front desk to ask for two toothbrushes. That call was the last known contact anyone other than Landell had with Locke. The following morning, Langdell placed the "do not disturb" sign on the outside of the hotel room door. He also called the front desk to request a late check-out and then left the hotel.

Later that same day, Langdell talked to a former girlfriend and his mother. As reported by the New York Post, he told both women that he had killed someone. However, he did not go into any detail. When Locke did not return home as expected, her family and friends became concerned for her welfare. As they knew she spent the evening with Langdell, they contacted his mother to ask if she had heard from her son.

The New York Post reports that Carl Langdell's mother confirmed she received a disturbing phone call from her son, in which he confessed he "killed a girl" and told her he was a "monster." Katie Locke's family contacted authorities immediately, and Langdell was subsequently arrested on suspicion of murder.

As reported by The Sun, Langdell confessed to strangling Locke to death in their hotel room. He then proceeded to sexually assault her lifeless body while taking photos with his cell phone. Langdell admitted to removing Locke's body from the hotel in a laundry cart and ultimately dumping her in a secluded area on the hotel grounds. Amid their investigation, authorities learned Langdell was not an attorney, nor was he studying law. Although he studied journalism at Hertfordshire University, he did not complete his degree. They also learned Langdell had an extensive history of mental illness, as well as sadistic fantasies and behavior.

In 2009, the Daily Mail reports that Langdell had his first known interaction with law enforcement when he was reported for assaulting a friend. Four years later, mental health professionals determined him to be a risk to himself when he became convinced he was being pursued by someone threatening him with bodily harm. Langdell also physically assaulted his brother in 2014. However, his brother refused to pursue criminal charges.

In February 2015, Langdell's mental illness and sadistic fantasies seemed to escalate, as he threatened to kill his girlfriend's sister and a mental health worker.

If you or someone you know is struggling with mental health, please contact the Crisis Text Line by texting HOME to 741741, call the National Alliance on Mental Illness helpline at 1-800-950-NAMI (6264), or visit the National Institute of Mental Health website.

As reported by the Bristol Post, authorities were called to the scene in February 2015, and Carl Langdell was detained and assessed by mental health professionals per the mental health act. During his assessment, Langdell confessed that he had been fantasizing about committing murder since the age of 6. However, he admitted the thoughts had become more intrusive in recent years, and the fantasies often gave him sexual gratification.

Although the mental health professionals ultimately determined Langwell presented a high threat to the safety of others — and to women, in particular — the results of the assessment were not provided to law enforcement officials. Langdell was arrested and criminally charged for the threats he made against his girlfriend's sister. Langdell pleaded guilty but was granted bail while awaiting sentencing. Per the conditions of his bail, Langdell had to remain at his parents' home and wear an ankle monitor.

On June 23, 2015, Langdell attempted suicide and was hospitalized in a trauma unit for two weeks. Upon his release, he was monitored closely by the community mental health team. However, he still managed to make more threats of violence, which were directed toward his girlfriend's brother. As local law enforcement agencies did not share information about Langdell's prior criminal history and Langdell's girlfriend refused to cooperate, criminal charges were never pursued. The Bristol Post reports that Langdell also avoided charges related to violating the terms of his bail.

In September 2015, Carl Langdell threatened to commit suicide and was hospitalized for mental health treatment (via the BBC). However, he was released again later that month. Hertfordshire Assistant Coroner Alison McCormick, who conducted the inquest into Katie Locke's murder, addressed the lack of communication between the law enforcement agencies at the conclusion of her inquest. McCormick said (per the BBC), "It is clear none of the organizations managing Mr. Langdell knew what each other knew about him. There was very little information sharing and no joined-up thinking or management."

Three weeks before he strangled and killed Locke, Carl Langdell was sentenced for the violent threats he made against his girlfriend's sister and the mental health professional. However, as the sentence was suspended, he was free to meet women online and go on dates. At the time of Locke's murder, Langdell admitted he was talking to as many as 20 different women on several different dating apps and sites. On at least one occasion, he took a date to the same hotel where he later killed Locke and dumped her body.

According to BBC, Langdell ultimately pleaded guilty to Locke's murder and was subsequently sentenced to 26 years at Wakefield maximum security prison. On February 11, 2021, Langdell was found unresponsive in a pool of blood on the floor of his cell. It was later determined that his throat had been slashed.

If you or anyone you know is having suicidal thoughts, please call the National Suicide Prevention Lifeline​ at​ 1-800-273-TALK (8255)​.

Although Carl Langdell was transported to the hospital, he was pronounced dead on arrival. As reported by The U.S. Sun, prison authorities are not treating the death as suspicious.

Katie Locke's death at the hands of Langdell, who she met through a dating app, has raised questions about the safety of dating apps in general. According to The Sun, the United Kingdom's Durham Constabulary alone received 545 reports of crimes related to people met on dating apps between 2011 and 2016. Throughout the U.K., authorities have received thousands of reports of assault, blackmail, rape, robbery, stalking, theft, and various crimes related to minors committed via dating apps or by people met on dating apps. The Sun reports that Tinder, Grindr, and Match.com are some of the more commonly reported dating apps. However, a vast majority of the reports have been related to Plenty of Fish. In fact, a startling 56% of the crimes reported were related to Plenty of Fish. Those statistics do not include attempted murders or murders linked to dating apps.

Unfortunately, most dating apps do not screen users. However, as reported by The Sun, users are encouraged to do their own research before sharing any personal information online. It is also suggested that users do not send money to anyone they do not know. If meeting in person, dating app users are encouraged to choose a public place they are familiar with and let their friends and family know where they will be and who they are with.