Bangkok Post

In the early hours of Feb 4, a call to the 191 police hotline reported the discovery of a half-naked woman's body in Pho Kaew Soi 3 in Khlong Chan of Bang Kapi district. The report was relayed to Lat Phrao police.

They found the body and dialled the number of the caller who had reported the crime to make further inquiries, but his phone was switched off.

Investigation Division chief Prayon Lasua was put in charge of the case.

His team had almost no evidence to begin with, except the body, which was of a woman believed to be in her early 20s.

She appeared to have been raped. She was naked from the waist down, her body had multiple cuts and bruises and a forensic examination later found she had suffered concussion from being struck in the head with a hard object.

Clumps of grass and weeds were clutched in her hands, suggesting she was alive when she was assaulted.

Pol Maj Gen Prayon assigned his deputy Pol Col Chayanont Meesati and intelligence specialist Pol Col Chutrakul Yosamadee to the case.

Their first tasks were to establish the identity of the victim and the man who reported the crime.

The caller's number was found listed in one of the police officer's phone contacts. The number belonged to "Ai Waen", the alias of a police informer. His real name is Suthee Boonprom, 23, a motorcycle taxi driver.

Police searched an area in a 5km radius of the crime scene.

At a house 3.5km from where the woman's body was found, a man identified her from a picture.

He was her partner, 24-year-old salesman Chanathip Laewongnil. He identified her as Apassara Todech, 20, and said they lived together in the house and had a nine-month-old son.

Mr Chanathip said he and Apassara had argued a few days ago and he had not seen her since.

He said he did not report her missing because it was not unusual for her to leave the house for that long to cool off after rows. She usually stayed at her mother's house in the Ekamai area.

Back at the police station, surveillance camera footage was examined.

One camera filmed Apassara getting on a motorcycle taxi in front of a 7-Eleven convenience store near her home in the early hours of Feb 4.

The last footage of Appasara was filmed by another camera nearby, which showed her riding as a passenger on the motorcycle at 4.03am.

When the same motorcycle was filmed by another camera 17 minutes later, the woman was not on it.

Police realised that camera was installed close to the home of Mr Suthee, who had reported finding Appasara's body.

He was immediately named the prime suspect in the case.

Police called at Mr Suthee's house but he was not home, so they questioned his mother and wife.

They told the police that Mr Suthee's motorcycle was parked outside an apartment in Navamin Soi 39. Officers then visited that property, but they still could not find the suspect. They seized his motorcycle.

As it was becoming apparent that Mr Suthee had fled, police grew more confident that he was their man.

They monitored incoming calls to his wife, and on Feb 9 officers detected that Mr Suthee called her from a payphone in Lom Sak district of Phetchabun.

Phetchabun police were alerted but failed to catch him at the public phone.

He was later caught at a nearby temple where he slept at night and lived off food donations. Mr Suthee allegedly confessed to killing Apassara.

He said the woman told him to take her from Lat Phrao Soi 101 to a 7-Eleven convenience store and then drive her to her house, police said.

Mr Suthee said he was drunk and stopped on the way to Appasara's house allegedly to sexually assault her. Police said he told them she resisted so he hit her on the head with a rock.

Contact Crime Track: crimetrack@bangkokpost.co.th