30 True Crimes That Changed Laws

30-True-Crimes-That-Changed-Laws

Welcome to WatchMojo and today, we’re looking at crimes that impacted the legal system and shaped the laws we live by.

Veronica Guerin
A tenacious investigative reporter, Veronica Guerin was one of the most well-respected journalists in Ireland during the 1990s. Known for building strong relationships with her sources, Guerin doggedly pursued her stories, occasionally putting her own personal safety on the line to secure interviews. She also did not shy away from contentious topics. Ultimately, her work covering organized crime led to her death when a South Dublin drug cartel ordered a hit on her in 1996. Following her murder, the Irish Parliament enacted the Proceeds of Crime Act and the Criminal Assets Bureau Act. These two acts enabled the government to seize assets bought with money acquired through criminal activity and led to the formation of the Criminal Assets Bureau.

Carl Starke
After her son was murdered in the parking lot just outside of her home, Anita Waring-Kennedy pushed to see a change in the law. On August 18, 2015, two men targeted Carl Starke, who had autism, while he was shopping at a store near his home. When Starke left, the men followed him, later killing him during a failed attempt to steal his car. In 2016, Carl’s Law was officially enacted in the state of Florida. The law permits the reclassification of criminal offenses when the victim involved has a mental or physical disability, thereby allowing officials to hand down harsher punishments.

Andrew Harper
On August 15, 2019, police officer Andrew Harper responded to a burglary in progress. While attempting to catch one of the suspects on foot, Harper got caught in a tow strap hanging from the back of the getaway vehicle. Harper was dragged for a mile before becoming disentangled from the strap. He was pronounced dead moments later. His death received national attention and resulted in significant public outcry. Harper’s widow launched a campaign to make life sentences mandatory for those found guilty of the manslaughter of emergency service workers during the commission of a crime. As part of the Police, Crime, Sentencing and Courts Act, Harper’s Law received royal assent in 2022.

Tracey Thurman
After months of horrific abuse and unrelenting harassment, Tracey Thurman was attacked by her husband in front of her home. A police officer was on the scene, but despite the brutality of the attack, the officer failed to intervene. In fact, Thurman’s husband went after her two more times during the incident, inflicting even further injury, before the officer finally arrested him. It took Thurman eight months to recover, and she was left partially paralyzed. In a landmark lawsuit, she sued the town and the police department for violating her civil rights. The case brought about significant change to domestic violence laws across the United States, including the Family Violence Prevention and Response Act in Connecticut, which makes arrests in domestic violence cases mandatory.

Dru Sjodin
On Saturday, November 22, 2003, Dru Sjodin wrapped up her shift at the local mall, did a little shopping, and then headed to her car. It appeared to be a typical day for Sjodin, but her friends and family began to worry when she later failed to show up at her other job. She was found dead the next week. Her murderer was identified as Alfonso Rodriguez, Jr., a convicted sex offender recently released from prison. Rodriguez was classified as a level three sex offender at the time, which indicated he was highly likely to re-offend. Following Sjodin’s murder, legislation was passed in 2006 that established the Dru Sjodin National Sex Offender Public Website. The registry allows users to access information about sex offenders nationwide.

The Manson Family Murders
While almost everyone is familiar with the infamous Manson Family murders, few people realize how the cult’s crimes affected the legal process. Following Sharon Tate’s murder, her mother, Doris Tate, became an activist who fought for victims’ rights. She joined the Victim Offender Reconciliation and Justice for Homicide Victims group. She was also instrumental in getting the Victims’ Rights Bill passed in 1982. Victims in every state are now allowed to give victim impact statements against violent attackers, either written or verbal, during the legal process. Doris Tate was even the first person to make a victim impact statement when her words were read aloud at a parole hearing for a Manson Family cult member in 1976.

Kayden Mancuso
Jeffrey Mancuso had a history of explosive anger and mental health issues. He disfigured a man in a fight in 2012 and mistreated animals in front of his family. But despite such violent tendencies, he was awarded unsupervised visitation with his daughter Kayden. Her mother fought to keep Kayden safe by seeking restraining orders, but it was no use. On August 6, 2018, after a scheduled visitation with her father, Kayden Mancusco was found dead in his home. Kayden’s grieving mother and stepfather fought to change custody laws, and in 2024, Kayden’s Law was signed by the Pennsylvania governor. The law strengthens existing safety conditions and restrictions to help prevent abuse in court-ordered visitation cases and increases the factors judges must consider before granting custody.

Dunblane Massacre
On March 13, 1996, a local shopkeeper walked into Dunblane Primary School in Dunblane, Scotland, and opened fire. In under five minutes, he killed 17 people and injured 15 others before taking his own life. The attack remains the deadliest mass shooting in UK history. In the wake of the Dunblane Massacre, grieving parents and activists called for significant gun reform. After intense public debate, private ownership of most handguns and semi-automatic weapons was banned the following year. Parliament also enacted mandatory registration for shotgun owners. In the decades since the Dunblane Massacre, there have been no other mass school shootings in the UK.

Helen McCourt
On February 9, 1988, Helen McCourt headed home after work. She had plans with her boyfriend and was anxious to prepare for her date. She never made it home. As evidence surfaced, it became clear Helen had met with foul play. Although her body was never found, authorities were able to gather enough evidence to convict local pub owner Ian Simms. McCourt and Simms had argued shortly before her disappearance. Helen’s mother advocated for new legislation concerning convicted killers who withhold information about their victims. Under Helen’s Law, offenders who conceal information about their victims face longer prison terms. The law received royal assent in 2020. Simms was released before the law was passed and later died without ever disclosing the location of Helen’s remains.

Mississippi Burning Murders
In June 1964, during the height of the civil rights movement, a major initiative was underway to register black voters in the southern United States. It was called Freedom Summer, and in Philadelphia, Mississippi, the Ku Klux Klan was not happy about it. They launched their own campaign — one of terror and intimidation — to counter the initiative. Three activists, James Chaney, Andrew Goodman, and Michael Schwerner, went missing and were later found dead. The murders ignited national outrage. Ultimately, 19 people were charged in connection with the crime, including the local sheriff. The events sparked landmark federal legislation prohibiting racial discrimination in voting — the Voting Rights Act — which was signed into law on August 6, 1965.

Clare Wood
Around the world, many women have lost their lives at the hands of their partners or ex-partners. On International Women’s Day in 2014, a law was implemented in England and Wales that could significantly reduce the frequency of such tragic incidents. Clare’s Law, also known as the Domestic Violence Disclosure Scheme, grants a person the opportunity to find out if their partner has a history of violent behavior. The law takes its name from Clare Wood, an English woman who was murdered by her ex-boyfriend George Appleton. Appleton had served prison time for violence towards women - a record that was unknown to Wood at the time. Today, other parts of the UK, Australia and Canada have all adopted Clare’s Law.

Daniel Morcombe
On December 7th 2003, Daniel Morcombe was last seen waiting for a bus somewhere in Queensland, Australia. According to reports, when the bus finally came, it failed to stop and pick him up because the driver was running late. Morcombe was apparently abducted shortly after by Brett Peter Cowan, a known predator, and he was declared missing until eight years later when his remains were found. In 2014, Cowan was arrested and sentenced to prison for life. As a result of the case, Australia implemented the ‘No Child Left Behind’ policy, which mandates bus drivers to always stop and pick up children, even if they can’t pay the fare.

Lee Rigby
Lee Rigby was a British Army soldier who lost his life in an attack on May 22nd 2013. Rigby’s assailants - Michael Adebolajo and Michael Adebowale - claimed to have carried out the attack in retaliation for the victims of British military action in Islamic countries. The two men waited at the scene until police arrived, upon which they were subdued and arrested. It is believed that Adebolajo and Adebowale had been radicalized to commit such a crime in the preceding years. In a bid to prevent further instances of this, then British Prime Minister Theresa May introduced the Counter-Terrorism and Security Act in 2015. The bill requires internet providers to keep records of users who access certain IP addresses.

Andrew Bagby & Zachary Turner
The 2008 documentary “Dear Zachary: A Letter to a Son About His Father” detailed the tragic case of Andrew Bagby and Zachary Turner. Bagby was an American medical student schooling in Canada when he met Shirley Turner. Their relationship produced one child - Zachary - who Bagby never got to see as he was murdered by Turner months before the boy was born. While out on bail, Turner gave birth to Zachary and remained in custody of him. However, before she could stand trial for Bagby’s murder, she took her own life and that of her son. After the documentary was released, Canadian parliament passed Zachary's Bill, which would deny bail to people on the grounds that doing so will protect their children.

The Chicago Tylenol Poisonings
You most likely won’t buy a bottle of over-the-counter drugs if its seal is broken. That level of assurance is only possible today because of the Chicago Tylenol incident. Back in 1982, several bottles of Tylenol were tampered and laced with potassium cyanide. As a result, seven people who consumed the lethal capsules in the Chicago metropolitan area lost their lives. This led to a nationwide recall of all Tylenol products by its manufacturer, Johnson & Johnson. The company also worked with the FDA to introduce sealed bottles, which has now become the industry standard. In 1983, it became a federal crime to tamper with consumer goods after U.S. Congress passed the Federal Anti-Tampering Bill.

Amanda Todd
In September of 2012, a video was uploaded on YouTube, in which a girl shared the story of her mental health issues using a set of flashcards. About a month later, the clip began gaining traction after it was reported that the girl, Amanda Todd from Canada, had taken her own life. According to reports, this was largely as a result of being harassed and blackmailed by a man online. Todd’s senseless death sparked national discussions on cyberstalking and mental health. This led Canadian politicians to pass Bill C-13, which makes it a crime to distribute private images of another person without their consent. It also includes provisions that could help law enforcement investigate and prosecute such cases.

George Floyd
The 2020 murder of George Floyd by police officers in Minneapolis, Minnesota sparked protests across the United States and around the world. In addition to demanding justice for Floyd, many demonstrators also called for broad police reform and an end to police brutality. Although the George Floyd Justice in Policing Act passed the House of Representatives, it faced opposition in the Senate and negotiations collapsed. However, in response to the incident, Presidents Donald Trump and Joe Biden both signed executive orders that addressed police training and accountability. In addition, more than 20 states in the U.S., and the District of Columbia, enacted laws around police reform aimed at preventing such tragic violence happening again.

Son of Sam
There have been various "Son of Sam" type laws introduced over the years, but the central goal is always the same: to prevent criminals from profiting from their crimes after conviction. This goes back to the fear that David Berkowitz, the notorious Son of Sam, would seek a book or movie deal while in prison to tell his story. Different states have drafted their own version of this law, only for some of them to be struck down as unconstitutional. In New York state, victims and their families will receive notification if the criminal earns more than ten thousand dollars from telling their story. It's a delicate balance between Freedom of Speech and profiting from tragedy.

Sylvia Likens
If you see a child being maltreated, you generally have only a moral obligation to inform the authorities. However, in the state of Indiana, turning a blind eye could result in you being charged with a crime. Referred to as the Mandated Reporter Law, this was enacted largely due to the murder of Sylvia Likens. Likens and her sister had been left in the care of Gertrude Baniszewski, while their parents traveled with a carnival. Instead of caring for her, Baniszewski, alongside some of her children and neighbors, made Likens’ life a living hell and caused her eventual death on October 26, 1965. Although some neighbors reported hearing Likens scream for help, not enough was done to save the girl’s life.

Matthew Shepherd & James Byrd
The two individuals in our next entry may not have known each other, but their place in history was vital towards the expanding of hate crime definition in the United States. The Matthew Shepard and James Byrd Jr. Hate Crimes Prevention Act was introduced and passed in the fall of 2009 after both men lost their lives as a result of prejudice and bigotry. The law not only made it easier for Federal authorities to investigate cases of this nature, but the Act also expanded wording to include crimes perpetrated due to one's gender or sexual identity. Although it cannot make up for the senseless loss of these two lives, it's arguably helped many people seek justice in the wake of such crimes.

The Port Arthur Massacre
The town of Port Arthur in Tasmania, Australia was the site of one of the most horrendous crimes in the country’s history. On April 28th 1996, Martin Bryant claimed the lives of 35 people and injured 23 others, using a semiautomatic rifle. The massacre shocked the entire nation and led to a nationwide debate on gun control laws in Australia. In the wake of the tragedy, the Australian government moved swiftly to introduce the National Firearms Agreement (NFA). This agreement significantly restricted access to automatic and semi-automatic weapons, and also included a buyback program for the newly banned firearms. Since then, Australia has seen a considerable decrease in gun-related deaths.

Emmett Till
In 1955, Emmett Till, an African-American teenager, was visiting relatives in Mississippi when he was lynched for allegedly flirting with a white woman. Despite overwhelming evidence of their guilt, Till’s killers were acquitted by an all-white jury. The trial and subsequent outrage over the verdict helped galvanize the Civil Rights movement and led to the passage of multiple landmark laws. In 2008, the Emmett Till Unsolved Civil Rights Crime Act was enacted, allowing for the investigation and prosecution of racially motivated crimes that occurred before 1970. This was followed by the Emmett Till Antilynching Act in 2022, which recognizes lynching as a federal hate crime. These laws serve as a commitment to seek justice for victims of racial violence.

Polly Klaas
Polly Klaas was taken from her home during a slumber party on October 1st, 1993, and the tragedy had far-reaching effects on California legislature. For starters, support for "three-strikes laws" earned a lot of traction. Her kidnapper, Richard Allen Davis, had a lengthy criminal record, though there were no open warrants when police initially stopped him after being notified of a suspicious car. The idea that felony criminals should serve automatic life sentences when they commit multiple serious crimes was made easy by Davis' repugnant and unrepentant behavior during the trial. Furthermore, California Highway Patrol expanded access to their all points bulletins to local authorities in the aftermath of Polly's death.

Rebecca Shaefer
Living life in the public eye isn't easy, especially when stalkers and obsessed fans come into play. This was unfortunately what caused the loss of a young and promising star, in the form of "My Sister Sam" actress Rebecca Schaeffer. Robert John Bardo stalked the actress for years, attempting to crash the set of "My Sister Sam," and even hiring a private investigator to find out where Schaeffer lived via the California Department of Motor Vehicles. Bardo eventually shot Schaeffer at her home, and her death prompted lawmakers to draft stricter anti-stalking legislation in its wake. The Driver's Privacy Protection Act was also made into law after this incident, making it more difficult for others to find personal information via the DMV.

Johnny Gosch
This cold case was the subject of a 2014 documentary titled "Who Took Johnny?" but it also changed how police respond to reports of missing children. Johnny Gosch was taken during his paper route on the early morning hours of September 5th, 1982, and he hasn't been seen since. At the time of his disappearance, policy in Des Moines, Iowa stated that someone couldn't be labeled as a missing person until 72 hours had gone by. The Gosch case resulted in legislation that changed all of this, making it easier for police to begin an investigation. "The Johnny Gosch Bill" requires authorities to immediately treat all missing person reports of a child as credible, and to respond accordingly.

Megan Kanka
How well do you really know your neighbor? This was the inspiration behind "Megan's Law," a subsection of laws that require the public to be able to access information of convicted sex offenders in their area. The specific case was that of seven year old Megan Kanka, whose neighbor Jesse Timmendequas lured and assaulted her before taking her life. Timmendequas' criminal history with little to no rehabilitation wasn't available to Kanka's family. And, as a local Assemblyman by the name of Paul Kramer was quoted saying, "Megan Kanka would be alive today" had a public registry been easily accessible by her family.

Ernesto Miranda
You've heard it a million times on television and movies, but do you know the actual origins behind your Miranda Rights? Although Ernesto Miranda was a criminal and his second trial did have the same results of a conviction, it's the circumstances of his arrest that changed the law. This was because Miranda wasn't informed of his right to remain silent, so as not to incriminate himself, and was also “refused an opportunity to consult with his counsel.” His confession was deemed inadmissible as evidence, and the state of Arizona had to retry him with said confession omitted from the record. The Supreme Court case, Miranda v. Arizona, now requires that all arresting officers inform you of your right to silence and an attorney.

Amber Hagerman
Most people are familiar with AMBER Alerts; they inform us whenever the case of a child going missing is reported in our area. However, it's vitally important that we remember the alert's namesake, Amber Hagerman. While riding her bicycle back in 1996, Hagerman was taken and murdered. Her killer has never been found. The case increased demand for immediate response to any sort of similar report involving minors, and today AMBER Alerts go out on radio, television, telephone, internet and highway communication devices in order to maximize public awareness and response. There are also related alerts for missing seniors, called Silver Alerts, and police, known as Blue Alerts.

Adam Walsh
The abduction and death of Adam Walsh is arguably the most well known case on this list, thanks largely to the public presence of Walsh's father, John, as the host of "America's Most Wanted." Still, it's impossible to overstate how much the Walsh Family has worked to help the families of victims over the years, as Adam's case was responsible, in part, for the establishment of the National Center for Missing & Exploited Children. Adam's taking from a Florida mall was also the impetus for the "Code Adam" program that's used in retail environments. An employee will now page information over the intercom to help find a child that’s been reported as having disappeared.

Kitty Genovese
Dialing 911 seems like such an instinctive act, it's easy to forget that this wasn't always how emergencies were called in to police. Kitty Genovese was followed, assaulted and stabbed by Winston Moseley while she was returning home after a late night shift working at a bar. The crime had multiple witnesses in the form of Genovese's neighbors, but some were reportedly too scared to call police, while others had difficulty getting through on a line. At the time, any emergencies would be called into the operator, who would then transfer the call to the appropriate authorities only when they had the opportunity to do so. This delayed response would, in part, influence the establishment of the 911 emergency system we use today.


Do you know of any other true crime cases that influenced the law? Let us know in the comments.