A teen who offered sexual services for money was excited about being pregnant when she left a motel where she was staying with her 40-year-old unemployed boyfriend, a jury has heard.
Tiffany Taylor who was aged 16 on that day in 2015 has never been seen since.
Rodney Wayne Williams pleaded not guilty in Brisbane Supreme Court on Tuesday to murdering Tiffany after she left the Waterford West motel room, south of Brisbane, on July 12.
The Crown alleges he and Tiffany arranged to meet that day for her to provide sexual services for money after they hooked up through a dating website, where she claimed to be 21 years old.
Tiffany took responsibility for earning money she and her boyfriend needed to live by pursuing a dangerous line of work, prosecutor Caroline Marco said at the start of the murder trial on Tuesday.
"Ms Taylor was a vulnerable child living a perilous life beyond the capabilities of her years when she met Mr Williams," Ms Marco added.
Jurors were told they would hear during the trial that Tiffany communicated with Williams - using the profile "muddles54" - and other men via the website Oasis.
In a profile description shown in court, "muddles54" states he is a "Master looking for submissive females", that he would love to teach the right girl the good life" and has been told he has a "magic tongue".
Ms Marco also showed the court Oasis messages during which Tiffany asks if Williams is "keen on sex for cash".
The conversation shows the "terms of agreement" for their meeting which included Williams agreeing to pay Tiffany $400 for 30 minutes of sex in his car, Ms Marco said.
The court heard Tiffany took only her mobile when she left the motel on July 12, and despite her usual "prolific use" of the phone, the last communication on it was a call to Williams' phone that went unanswered at 11.48am on that day.
Ms Marco told the jury the Crown's case is that Williams drove the teen to an industrial estate at Larapinta where he stopped for about 20 minutes before driving west beyond the Ipswich area.
It was there, the prosecution argues, Williams disposed of the teenager's body.
The Crown alleges evidence shows Tiffany's increasing desperation in trying to provide sexual services in exchange for money so she could pay bills.
It also showed her reticence to meet anyone unless they agreed to pay and her intention to limit the time of her interaction with them, Ms Marco said.
Ms Marco said Tiffany did not disappear without a trace, leaving her image on motorway cameras, details of her location on cell phone towers, and her blood and DNA in Williams' car.
The Crown would show footage it argues shows Williams and Tiffany together in his gold or champagne coloured Hyundai with a "Hustler" sticker on the back bumper.
Prosecutors also allege Williams tried to leave Brisbane with a bag of clothes and sentimental items on August 13, the day before he was due at a police interview.
Searches, after the teen was reported missing by her sister on July 15, failed to uncover her body.
Williams' barrister Kim Bryson told the jurors her client had lied to police but did not kill the teen.
"After you've heard all of the evidence in the trial I will be in a position to present you with the reasons why you will find Rodney Williams not guilty," she told jurors.
Ms Bryson asked them to pay particular attention to evidence about Tiffany's violent and controlling boyfriend, saying evidence would give insight into their "abusive and dysfunctional relationship" that started when the girl was 12.
The trial set down for about four weeks before Justice Peter Applegarth is expected to hear from more than 60 witnesses.
