One of the worst crimes of 2016 wasn't cold-blooded murder. It was cold-blooded treatment of victim after victim by self-styled hi-so Ying Kai. Here are our top crime stories of the year.

1 Rape and murder in Trang

One horrific case involved a young man who was murdered and buried while the attackers raped his girlfriend and threw her into an ditch in the southern province of Trang.

On Feb 27, in a thick forest in the Ban That mountain range, a group of young people killed an 18-year-old teenager and buried his corpse before raping the victim's girlfriend, stabbing her with a knife and bludgeoning her with a hard object before tossing her into a ditch not far from Phetchakasem-Phatthalung road in Trang's Na Yong district.

A police investigation into the murder revealed the crime involved seven attackers. Police and Crime Suppression Division investigators later detained five suspects -- two 19-year-old male youths, Sirima Phuphuak, 20, and two other youths, aged 15 and 17. They were charged with murder and rape.

Police obtained key evidence from the rape victim who miraculously survived. The evidence led to the arrest of other suspects. On March 25, Si Nakharin district police detained the sixth suspect, a 19-year-old male, and charged him with detaining a person. Later on March 29, a 15-year-old female youth turned herself in to face similar charges. Police had information she was the person luring the boyfriend and his girlfriend to the crime scene.

The female suspect denied any wrongdoing though she admitted she was a former girlfriend of the murdered victim. Police said she used her mobile phone to call the male before he was killed. She told investigators her relative had borrowed the phone and pretended to be her to lure the victim. Despite admitting she had been to the crime scene, she claimed she was not there the day of the murder.

But the evidence investigators had uncovered told a different story. She allegedly lured her ex-boyfriend and his new girlfriend to meet her in front of a local temple where the two were forcibly taken to the murder scene in the Ban That mountain range.

Other pieces of crucial evidence included Facebook Messenger conversations between the gang members and those between the gang and the male victim. These were forwarded to the prosecution.

Well-known actress and TV host Panadda Wongphudee, who runs a charity foundation, is credited with pushing police to work harder to bring the culprits to justice in this case. Following media reports about the murder and rape case, Ms Panadda accused some police officers of stalling the investigation. The comment put pressure on police who subsequently stepped up the probe which was concluded in slightly over a month.

2 Ying Kai

Having pretended to be a khunying for many years for the purpose of defrauding people, Monta Yokrattanakan, better known as Ying Kai, became one of the most controversial fraud and lese majeste suspects in 2016 after one of her many victims came out to seek help from a volunteer lawyer who exposed Ms Monta's alleged long history of criminal acts.

Ying Kai was no khunying after all.

On June 22, Songkan Atchariyasap, the lawyer who chairs the Network Against Acts that Destroy the Kingdom, Religion and Monarchy, took a 19-year-old female identified only as Praphawan or Nong Koi, a first-year engineering student, to lodge a complaint with the Crime Suppression Division, accusing Ms Monta of filing a false theft charge against the teenager and her parents.

In the complaint, Ms Monta was named as the girl's former employer who had claimed to police that the youth and her parents had stolen valuables of hers worth more than 10 million baht on March 18 and laid a false theft charge against them.

The youth's complaint made headlines and led to probes into the woman's background. At that time, she was widely known as Ying Kai, a nickname leading the public to misunderstand that she had the royally conferred khunying title.

And, as the media dug deeper, they found several other alleged victims who said they also were former employees of Ms Monta who had also been mistreated. Some of the former employees had been sent to jail for thefts they did not commit. They were each accused of stealing the woman's valuables worth several million baht.

And as the media dug deeper into the cases involving Ms Monta's prosecuted employees, the public began to suspect whether she actually was a khunying. Among the former employees were Chanthana Khotchakhongthai, 25, and Thanathip Sising, 32, a husband and wife from Mae Hong Son who had served three years in prison in a theft case Ms Monta had pursued against them.

Nong Koi was later proven innocent in the theft case. Some police at Pracha Chuen police station, meanwhile, were facing an investigation over their alleged involvement in assisting Ms Monta to cook up cases and falsify evidence, which helped the woman to win legal battles against her former employees, many of whom had been jailed.

Police also found Ms Monta had illegally cited the higher institution in her own interests, which is deemed a violation of Section 112 of the Criminal Code, or the lese majeste law. Ms Monta was later detained and jailed briefly before she was released on bail and is still fighting the case in court.

3 Passport gang

In September, a crackdown on a transnational passport forgery gang led police to the discovery of a dismembered body of Western man at the gang's hideout in Bangkok.

On Sept 23, Phra Khanong police were alerted to the injury of a police officer during a raid on the fake passport network at a shophouse on Soi Sukhumvit Soi 56 in Phra Khanong district. Upon arriving, they found that Pol Sgt Maj Kanchanapong Chedet had sustained a gunshot wound and sent him to hospital.

Three foreign nationals including the prime suspect, British national Peter Andrew Colter, 66, were nabbed at the scene. Three pistols, illicit drugs and fake passports were impounded.

Peter Andrew Colter confessed to murder.

However, as police searched the house to gather evidence, they were startled by the discovery of six body parts, later proved to belong to a Caucasian man, inside a large freezer. According to an investigation, the corpse was identified as that of Charles Edward Ditlefsen, a US national. He was believed to have been dead for more than seven or eight years.

Mr Colter, who first denied involvement in the death of the victim, later confessed to police that he and his gang members killed Ditlefsen. The suspect said they strangled the victim and dismembered his body in 2008 as the victim owed the gang money.

In a separate case, the dismembered body parts of an Israeli man were also retrieved from a wall inside a house owned by the victim's fellow national in Nonthaburi in November.

On Nov 12, Mr Shimon Biton was nabbed during a raid on his rented two-storey townhouse where he lived with his 17-year-old son in Bang Bua Thong district. The operation was carried out by the Crime Suppression Division (CSD) after the agency was asked by the Israeli embassy to search for Eliyahu Cohen, a 63-year-old former Israeli police officer, who was reported missing on Nov 7 from a condominium in Bangkok's Bang Phat district. Cohen's relatives had previously submitted a petition to the Israeli embassy about his disappearance.

According to police, Mr Biton killed Cohen and hid his dismembered body parts inside a wall following a heated argument over a woman. Police found three black bags after noticing a stench and knocking two bricks from a wall which they said looked out of place. The bricks were covered with concrete.

An initial investigation found the first bag contained a severed head; the second contained a left leg with a black sock; and the third, the largest bag of the three, contained parts of the torso and a right leg.

Mr Biton, who was in the house during the raid, allegedly told police he killed Cohen on Nov 9 out of jealousy after discovering his girlfriend had been involved in an intimate relationship with the victim.

4 Jimmy the serial killer

Early in October, the killing spree of three homeless victims in Pathum Thani and Bangkok prompted a manhunt for a suspected serial killer who later turned out to be a Myanmar national identified as Jimmy.

Mr Jimmy's DNA linked him to the murders.

The charges were brought against the 20-year-old man after DNA test results indicated he was behind the deaths of the three people in Pathum Thani, as well as two other victims in Bangkok who were killed in a similar manner between September and October. With images from security camera footage obtained by police, Mr Jimmy was arrested near Mor Chit Bus Terminal on Oct 7 after police spotted the suspect wearing a bloodstained shirt.

Mr Jimmy's physical appearance matched the image of the suspect in the footage captured of him in the earlier killings. He had previously ridden his bicycle from Pathum Thani to Bangkok, according to the investigation.

During police questioning, he insisted the blood was his own and was the result of a self-inflicted wound. Lab tests later confirmed the blood belonged to some of the dead victims, according to the investigation team led by Metropolitan Police Bureau chief Sanit Mahathavorn. The forensic evidence and the similar nature in which the victims were murdered led police to conclude that Mr Jimmy must have killed the three men and two women.

On Oct 4, the bodies of a man, Supakorn Kokkran, 25, and a woman, Supaphan Kongyudee, 35, were found near the Princess Mother National Institute for Drug Abuse Treatment, also known as Thanyarak Hospital, in Pathum Thani's Thanyaburi district. Their bodies were found with their throats slit and their hands tied with electrical wire.

Two days later, the body of a third victim, Sathien Sornchai, 48, was discovered near the same hospital. His throat was slashed and there were stab wounds to his abdomen and buttocks. His hands were also tied with electrical wire, as were the first two victims.

Investigators believe the victims fell prey to the same killer because they were murdered in a similar manner. DNA test results also showed some of the bloodstains on Mr Jimmy's shirt carried Supakorn and Sathien's DNA.

On Oct 9, not far from where Mr Jimmy was caught, the body of a fourth victim was also found.

5 ATM Heist

Solving a crime is rarely a straightforward business as exemplified by the ATV heist case in Suphan Buri which combined a diversion tactic and an insider job.

A carefully-planned and orchestrated robbery of an ATM at a PTT petrol station on Song Phi Nong-Wat Phai Rong Wua road in Song Phi Nong district had police detectives veering off course for a while before they realised the lead and evidence they picked up was intended to fool them.

More crime suppression officers were sent to work on the case alongside local police. What they had to start off with in their investigation was the robber's clothes and helmet. But what struck them the most was a Samsung mobile phone the robber had dropped, apparently by accident, in staging the heist.

The phone was to be the prime evidence for investigators.

The detectives scrolled through the call history on the phone. The robber called 22 numbers prior to the heist. The call pattern suggested the robber dialled the numbers and immediately hung up the phone before the numbers could answer.

The police then tracked the person who bought the phone and the SIM card. As it turned out, the ID card number used to purchase the phone belonged to a female drug offender in Suphan Buri.

After police checked the woman's personal information, one piece of information stood out -- her ID information stored in the Civil Registration database had recently been copied by someone using the Royal Thai Police's computer system that was linked to the Civil Registration database.

The person who copied the woman's information was a police officer at the Ban Bung police station in Chon Buri.

The officer in question who committed the ID theft was Pol L/C Withoon Phechpankan, an award-winning, young detective. Investigators say they managed to identify the ATM robbery gang members from questioning Pol L/C Withoon.

The gang members were identified as Chaidech Phechpankan, an older brother of Pol L/C Withoon; two other men, Somnuek Somsuay and Suchao Chaengdi; and two youths by the names of Toon and Fa.

Police found Pol L/C Withoon hatched the robbery plot. He gave his brother 5,000 baht to open a popcorn stall at the Suphan Buri petrol station to observe a cash delivery to the ATM three days before the robbery. Pol L/C Withoon was brought in for police questioning. He was accused of driving Mr Suchao to the shop to buy the Samsung phone on Nov 6. They used the citizenship ID number of the female drug offender Pol L/C Withoon had stolen to purchase the phone and a SIM card.

Mr Chaidech allegedly wore a bulletproof vest owned by Pol L/C Withoon while carrying out the robbery.

Pol L/C Withoon's statements confirmed the investigators' theory that the gang had dropped the mobile phone intentionally in the hope that police would be busy sorting out the phone information which would stall the case and give them more time to escape, according to police in charge of the case.

According to police, Mr Chaidech robbed the ATM because he was in financial trouble and enlisted his brother's help in staging the robbery.

A week after the robbery, the whole gang was arrested. Police managed to retrieved most of the stolen cash.