Christchurch sex worker Renee Duckmanton was happy and saying, "awesome this, awesome that" on her way to work the night she was murdered, her minder told a court today.

Sainey Marong, a 33-year-old from Gambia, is alleged to have picked up Duckmanton from Christchurch's red light district before strangling her to death, dumping her body on the side of a country road, and setting her on fire, the High Court in Christchurch has heard.

Marong denies murdering Duckmanton on or about May 14, 2016. His defence says the evidence will be best understood through a "lens of mental imbalance".

The second day of the trial heard from Terry McGowan, who often acted as a minder for Duckmanton while she worked at nights, the court heard.

McGowan told how he picked her up on the evening of May 14 and took her to the intersection of Peterborough and Manchester Sts.

When she got in the car, she "started talking 16 to the dozen", and everything was "awesome this, awesome that", McGowan said.

After they pulled up at the red light district, she sat in the car, did her makeup, put on lipstick, brushed her hair, and "got ready for whatever she was going to do", McGowan told the court.

She left her purse with him, which was normal, he said.

Later, she told McGowan she was going on a job for an hour. He never saw her again.

"I just sat in the car, listened to music," McGowan said.

Asked by Crown prosecutor Pip Currie how long he would wait, he said: "I would wait until she wanted to go home."

He soon got concerned text messages from Duckmanton's boyfriend Samuel Doak.

At 11.01pm, McGowan phoned Duckmanton but it went straight to voicemail. He said that by then he was also worried.

He texted Doak that there was nothing they could do except wait.

McGowan waited until 2am before going home.

Yesterday, Doak claimed that Duckmanton told him she was going with the same client who had locked the car doors on her about three weeks earlier, and she had to walk home from a job.

Giving evidence today, Doak said he asked her if she felt safe.

"'Yeah yeah, I'm fine. Stop ringing because he's getting annoyed'," she told Doak.

The Crown says its case against Marong is "overwhelming", with DNA samples taken from Duckmanton, and also samples found where her body was dumped, allegedly belonging to Marong.

A sheep's tongue "bizarrely" found at the scene is alleged to have come from an animal that Marong helped butcher the day the sex worker went missing.

Police examinations of Marong's mobile phone, the Crown alleges, "deeply implicates" him in the murder.

Weeks before the alleged murder, the Crown says Marong searched the internet for what kidnappers use to make people unconscious, chloroform, and is claimed to have clicked on an article entitled, 'How to kidnap a girl: an informative guide'.

There were also multiple searches about necrophilia, including a "man having sex with dead body".

McGowan told how he met Duckmanton one night one his way home from the cinema.

"[I] stopped and talked to her on a whim and we got on really well. She was an amazing person," he said.

The trial, before Justice Cameron Mander, continues.