Teo was reported missing four days after she disappeared, and there were both search efforts and investigations made to trace her whereabouts.

The second suspect, Ragil Putra Setia Sukmarahjana, was on the police's wanted list and remains at large outside Singapore.

Police investigations revealed that Teo last went to the 10th-floor flat of two male schoolmates at Marine Terrace on 30 June 2007.

The two friends told police that Teo went to their shared flat and stayed until about 2:00 AM on the morning of 30 June before leaving on her own.

Since her disappearance, 100 friends and relatives have searched at Teo's favourite hangouts, including Marine Parade, Clarke Quay and East Coast.

Additionally, Teo had plans for an internship at a leading advertising firm, and had also bought tickets for a concert in August that year.

One of these items was found to be in the possession of Ahmad Danial bin Mohamed Rafa'ee, a Malay Singaporean, one of the two male friends who she visited on the day of her disappearance.

It was alleged that between 1:39 AM and 7:20 AM on 30 June 2007, Ahmad and his Indonesian friend, Ragil Putra Setia Sukmarahjana, had killed Teo inside their flat and disposed of her body by unknown means.

Ahmad, who goes by the alias Danial Enemiko on his social media accounts, studied for a diploma in communication design and advertising at LASALLE from 2000 to 2004.

He also worked many filmmaking jobs based in Jakarta, Indonesia, and was last known to be employed as a director's assistant at the time of Ahmad's capture.

[15] Upon the news of Ahmad's arrest, Teo's family declined to speak to the media, citing their need for privacy.

[18][19] Teo's alleged murder also gave hope to the family of Lim Shiow Rong, a seven-year-old girl who was raped and murdered by an unknown person in 1995; in view of the renewed attention to Teo's case, Lim's mother and sister made a public appeal for new information to help solve the case and locate the killer, who has not been caught.

After he was charged, Ahmad was held at the Tanglin and Central police divisions and was scheduled to return to court on 24 December.

[23][24][25] Defence lawyer Shashi Nathan and two other colleagues from his law firm, Withers KhattarWong, would represent Ahmad in his murder trial.

The case was adjourned to 31 December 2020, and on that day, Ahmad was further remanded for one more week due to an unspecified health condition.

[27][28][29] On 28 January 2021, Ahmad's final psychiatric report was completed and would be used as evidence to assess his mental state at the time of the offence.

[30] On 24 May 2022, it was reported that Ahmad's remand order was extended and still in effect, while police continued to search for Ragil, who remained at large outside Singapore.

[33] On 27 June 2022, Ahmad was granted a discharge not amounting to an acquittal for Teo's alleged murder, but it can be revived if the prosecution finds additional evidence against him.

Ahmad, who was offered a S$20,000 bail, was scheduled to return to court on 6 July 2022 for trial, after he expressed his intention to plead guilty to the lower charges.

However, the guilty plea was adjourned and a pre-trial hearing would be conducted on 5 August 2022, as the prosecution and defence needed to have discussions and resolve several issues.

[44] While the appeal was being processed, the full grounds of decision by District Judge Eugene Teo were released on 12 August 2022.

Ahmad's lawyer Shashi Nathan, who earlier sought a 18-month term of imprisonment, argued that Ahmad was genuinely regretful of his actions but failed to muster sufficient courage to tell the truth for fear of losing his family, life, reputation and career, and also expressed his intention to apologise to Teo's friends and family for the emotional torture he put them through.

The seriousness of the charge faced by Ahmad was also supported by the public interest, which revolved around the need to resolve investigations, which was more of a priority than Ahmad's own personal interest in being freed from the hardships (including the rejection of his new passport application) that come from having an unresolved murder charge hanging over him.