Nirut Sonkhamhan

On January 3, 2012, Sonkhamhan supposedly poisoned and robbed a man named Watchara Suebchuea, whose body he dumped off a bridge between the Sawi and Thung Tako districts, but the body was never located. Later that month, Sonkhamhan attempted to do the same to a taxi driver named Charoen Daranoi, who realized that he was being poisoned and kicked him out of the car before speeding away. At the very end of January, he poisoned his sixth victim, Paitoon Pattalapho, whom he dumped at a sugarcane plantation in the Cha-am district, unaware that he had survived.

After reviewing CCTV footage of the client last seen with the victims and Srichampa's stolen car, authorities tracked down Sonkhamhan to a hotel room in the Sam Phran district, where the Crime Suppression Division subsequently arrested him. He was subsequently brought to the Khlong Wan Police Station and put in solitary confinement, where he attempted to hang himself with an electric cord on April 17, 2012, but was saved after prison guards found him and cut it off.

On January 11, 2011, the body of the first victim, 67-year-old Yupin Jeonkhem, was found floating in the Lampao Dam, having been weighed down with cement blocks. By examining fingerprints imprinted in front of the victim's house, police determined that the perpetrator was Sonkhamhan, and an arrest warrant was subsequently issued for his arrest.

Nirut Sonkhamhan (Thai: นิรุต สอนคำหาร; August 5, 1969 – April 18, 2012), known as The Pickup Truck Killer (Thai: ฆาตกรรถกระบะ), was a Thai serial killer who poisoned nine taxi drivers from 2011 to 2012, six of which died as a result. Sonkhamhan was arrested and charged with the murders, but hanged himself in his jail cell before he could go to trial.

Nirut Sonkhamhan was born on August 5, 1969, in the Nong Kung Si district. When he was ten years old, he moved with his father to Songkhla, where Sonkhamhan remained until the age of 25 when he moved to the village of Khok Krua. There, he married and started a family, and found a job as a taxi driver, but experienced financial difficulties due to his gambling habits.