How crime scene interference stalls major crime cases

Investigators and criminologists apply the principle ‘every contact leaves a trace’ to crack crimes while attempting to understand their patterns.

Coined by French criminologist Edmond Locard, the rule holds that the perpetrator of a crime will bring something into the crime scene and leave with something from it, and that both can be used as forensic evidence.

Over the years, it has come to be known as the Locard’s exchange principle, which underlines why every crime scene must be treated with utmost care – that the integrity should be maintained, evidence safeguarded and contamination minimised.

The crime scene is one of the primary foundations of police investigations. Finding, recording, and gathering physical and biological evidence is key in investigations.

Since the case being investigated must be presented in court, the process must be thorough while piecing together the evidence to create a picture of what actually transpired.

Since evidence is the backbone of justice, exhibits at a crime scene are crucial in nailing the culprit(s). When the integrity of the scene is in question, or contaminated, justice is not guaranteed – either culprits walk free or innocent people are linked to the crimes.

But in Kenya, most crime scenes are poorly secured and mismanaged leading to contamination of evidence.

Lawyer’s assassination

Many crimes remain unresolved partly as a result of poorly managed crime scenes with the latest case being the killing of lawyer Kyalo Mbobu who was executed in a drive-by attack on September 9 on Magadi Road.

A month later, detectives pursing the two killers who were riding a motorbike are yet to make a breakthrough.

The incident, is a classic example of a bungled crime scene. By the time police arrived, the integrity of the scene had been compromised by curious onlookers who milled around his car while taking photos and videos of his body slumped on the steering wheel.

There were unconfirmed reports that impatient motorists moved the stalled car from the primary scene to open the road for passing since it had blocked that particular narrow stretch where gridlock was building.

Since the scene was left unsecured, the interference contaminated crucial evidence that could have made the work of investigators even lighter in pursuit of the killers. The stretch did not have CCTV coverage, hence detectives heavily rely on physical evidence collected at the scene.

One of the most important aspects of securing the crime scene is to preserve the scene with minimal contamination and disturbance of physical evidence.

In Kenya, the public barely understand the importance of safeguarding the scene of crime. Many are the times crowds flood crime scenes, completely destroying crucial evidence.

“Crime scene management is not just a technical task, it’s the cornerstone of justice. When done right, it ensures that every victim gets justice, every suspect gets a fair trial, and every piece of evidence speaks the truth,” says Chrispine Owano, an expert in forensic investigations.

In Owano’s view, challenges like public panic, inadequate logistics, untrained responders, and political interference can disrupt the process.

“With the right training, planning and teamwork, effective crime scene management is possible,” he notes.

Scientific evidence

But securing crime scenes has never been a priority, neither an easy task. Even after general duty officers arrive, they struggle to keep at bay the crowds. By the time scenes of crime experts start work, the integrity of the scene has already been badly compromised.

Former director of Criminal Investigations Department (CID), renamed Directorate of Criminal Investigations (DCI) Joseph Kamau, is advocating for public awareness, arguing that crime scenes hold the scientific evidence that should be secured at all cost.

“A scene of crime reveals to the detective everything; the profile of the criminal, the characteristics of the criminal – whether they are professionally trained or just amateurs. A criminal must leave something at the scene, and that’s why the scene must be secured,” explains the seasoned detective.

Crime scenes, according to the ex-CID boss, help police understand the nature of crimes and their patterns – and that is why it’s advisable to document minor details gathered.

“It is important to preserve the evidential value before investigators take over because without it, investigators end up relying on circumstantial evidence, which is not sufficient,” says Kamau citing the 2004 attack of renowned writer Ngugi wa Thiong’o and his wife Njeeri as one of the successful probes resulting from a secured crime scene.

“The attackers had cut a hole in the fence to create the impression that the criminals came from outside, when in reality they were right inside the apartments. And that is how we were able to narrow onto the guards,” recounted Kamau.

Ngugi, who died in May this year, was beaten by four men during a homecoming after 22 years in exile. His was raped and burnt with cigarettes during the night ordeal at the hotel apartments the couple was residing in Nairobi.

Three security guards Richard Kayago Maeta, Elias Sikuku Wanjala and Peter Mulati Wafula were convicted and sentenced to death by principal magistrate Julie Oseko. Ngugi’s nephew, John Kiragu Chege, was cleared of charges.

However, there are many complex crimes in Kenya that remain unresolved, especially murder cases, which experts say remain cold because the evidence is not concrete.

Some of these murders are those of Dutch tycoon Tob Cohen, controversial businessman Jacob Juma, Independent Electoral and Boundaries Commission (IEBC) ICT manager Chris Musando, IEBC officer who was in charge of Embakasi East Daniel Mbolu Musyoka, University of Nairobi student Mercy Keino, Kenya Power employee Careen Chepchumba, and Jomo Kenyatta University of Agriculture and Technology student Rita Waeni, among others.

Innocent suspects

Notably, integrity of scenes where these individuals were murdered was deliberately compromised by the killers – and this may explain why investigations collapsed.

Any interference destroys evidential value. From a forensic perspective, failure to secure a scene has consequences because once forensic experts come in for fingerprint or DNA analysis, some of the first responders are profiled as persons of interest simply because their prints are all over the exhibits.

This how in some cases, real culprits escape as innocent people end-up being suspects.

One of the glaring gaps in managing crime scenes, according to Owano, is the slow response by the police.

“The response time to secure the scene is critical; the lesser the time the high chances of safeguarding evidence. Unfortunately, our level of handling crime scene is not professional,” says Owano citing the recent crashing of an Amref light aircraft in Mwihoko, Kiambu County.

At the scene, first responders before police arrived, were seen carrying away metal debris while crowds milled around the August 7, 2025 accident that left six people dead.

The Mwikoho incident came not long after questions were raised on how police handled the scene following the shooting of Kasipul MP Charles Ong’ondo Were.

Kware bodies

Lawyer Miguna Miguna was among the first people to express disappointment at the “unprofessional” handling of the scene.

“The DCI’s complete ineptness is legendary. They entered the vehicle with potential suspects and ransacked it before driving it away. I couldn’t believe my eyes,” posted Miguna on social media.

According to Miguna, the car should have been secured and towed by a forensic team.

East African Legislative Assembly MP Winnie Odinga who was among those at the scene expressed similar concerns: “why are there passengers in the crime scene vehicle? What kind of investigation is this?”

The Kware dumpsite, where six dismembered female body parts were discovered in July 2024, is another example of how interference compromises investigations.

By the time authorities purported to be securing the scene, local volunteer divers and members of the public, some with bare hands, were half-way through retrieving some of the bodies.

Collins Jumaisi Khalusha, 33, was arrested and “sensationally” claimed he had killed 42 women since 2022, including his own wife. The man would later mysteriously “escape” from Gigiri Police Station where he was being detained.