DNA of five men found in Tob Cohen murder probe

Sarah Wairimu before the Kibera High Court during the Tob Cohen murder trial. [Nancy Gitonga, Standard]

The mystery surrounding who entered Dutch billionaire Tob Cohen’s Kitisuru residence before his death has deepened after a forensic analyst revealed DNA profiles of five unidentified men recovered from items collected during investigations.

Former Government Analyst John Mungai on Thursday told the Kibera High Court that forensic tests generated DNA profiles from pillows, a steering wheel, a metallic door, a white towel and other items collected from Cohen’s home and vehicles.

Some of the profiles, he said, belonged to several different unknown male persons, raising fresh questions over whose biological material was found on items examined after the Dutch businessman’s death.

Mungai, who holds a Master’s degree in Forensic Science and retired from government service in 2021, told Justice Diana Kavedza that he had analysed more than 70 items.

He said his examination was undertaken following a request by Inspector Clement Mwangi of the Serious Crimes Unit’s Homicide Division who delivered numerous exhibits to the Government Chemist laboratory in Nairobi on September 20, 2019.

Among them were a rope used to tie Cohen’s recovered body, which was found next to his toes, fingernails, urine bottles, two teeth, hair strands from the deceased’s head, water bottles, leaves from the compound, cartilages and a blood sample from Cohen’s chest cavity.

Further exhibits included swabs from motor vehicle KAD 858S, a yellow lighter, hair strands and 17 cigarette butts.

They were displayed in open court and outside the courtroom, with Sarah Wairimu Kamotho, the widow accused of murdering Cohen seen visibly emotional as Mungai tendered them one by one.

Other exhibits included swabs from vehicles KZQ947 and KBW171G, coffee mugs and empty water bottles from Cohen’s glove bag.

But it was the DNA findings that provided one of the most damning part of the testimony.

Mungai told the court that DNA profiles generated from several items did not match either Cohen or his widow Wairimu.

While explaining the profiles, he said DNA profiles from a tap knob, an empty water bottle, a white towel and a grey toothbrush contained profiles “of different unknown male persons.”

"Of the steering wheel from motor vehicle KZQ947....generated a DNA profile of unknown male person," Mungai said.

The DNA generated from the white pillows from the master bedroom also belonged to a different person, he told the court.

The court was also taken through exhibits recovered from Cohen’s body, clothing, vehicles and compound, including deep-muscle swabs from his right leg, tissue swabs from near his collarbone, a femur bone, two teeth, fingernails, a white substance recovered from his jeans, hair and other material.

The analyst also identified Cohen’s blue jeans, woollen jumper and belt, together with a black curtain recovered from inside the water tank where his body was found.

A second black curtain, red dressing robe and yellow polythene bag covering the body were also examined.

Three towels, pillows, toothbrushes and other household items were among the exhibits presented in court as the forensic evidence was being tendered.

Mungai also compared DNA profiles generated from exhibits with reference samples obtained from Wairimu.

He told the court that the DNA profile generated from tissues collected from Wairimu’s bedroom matched her reference profile.

He explained that DNA testing involved examining different regions of the genetic code and identifying inherited segments.

The court also heard evidence relating to Cohen’s DNA profile.

Mungai said analysis of cartilage samples established that Cohen was male, with XY chromosomes.

 "Cohen has inherited 12 fragments of DNA from one biological parent," he told the court, "and 14 DNA fragments from the other biological parent."

Swabs from Cohen's sister, Gabrielle Hannah-Cohen Van Straten, and brother, Bernard Cohen, were also examined as reference samples.

The forensic revelations came against the backdrop of evidence from witnesses who interacted with Cohen during his final known hours.

Waiter Michael Wainaina told the court that Cohen left Plums Hotel in Parklands between 12.30am and 1am on July 20, 2019.

Cohen sat at the counter and was joined by a woman known as Margaret Wanjiru.

He said Wanjiru later left Cohen to dance before two other women joined the businessman.

According to Wainaina, Cohen bought the women drinks before Wanjiru returned and caused a disturbance.

He said Cohen subsequently walked away, requested music and began singing before indicating that he did not want to see Wanjiru again.

At about 1.45 am, Wainaina said, Wanjiru confronted a bouncer identified as Hillary, whom she allegedly scratched and whose shirt she tore.

“She was drunk and violent not to Cohen, but to the bouncer,” Wainaina told the court.

The waiter said Cohen was then assisted by security, got into his vehicle and drove away alone.

Bartender Aggrey Ingano gave similar evidence, telling the court that Cohen drank, sang and danced before announcing that he was leaving.

Ingano said Cohen did not want to be followed and that he warned the woman who had been with him against following the businessman.

The two witnesses' accounts placed Cohen alone in his vehicle when he left the Parklands establishment, hours before his disappearance.

Cohen later disappeared and his body was discovered in a septic tank at his Kitisuru home.

The murder trial will resume on October 12 and 14, when 12 witnesses are expected to testify over the two days.