When he took the witness stand last October to give his version of events, Pierre Chng Yuheng, 19, was on his best behaviour.
Yesterday, when he took the stand again to be cross-examined by the prosecution, he was like a different person.
When questioned, he crossed his arms, glared at the ceiling and refused to answer.
He even used his mobile phone while on the stand. He also branded the trial "biased and prejudiced", demanding that the judge presiding over his case be replaced.
The full-time national serviceman, who faces two charges of criminal intimidation, responded the same way to almost every question. He said loudly: "This court proceeding is grossly biased and prejudiced. This is malicious prosecution. This is persecution.
"I have judicial rights. I demand a change of court, judge and DPP (Deputy Public Prosecutor)."
Chng, who is representing himself, repeated this more than 10 times yesterday.
His two counts of criminal intimidation were allegedly against his family's former landlady, Madam Khoo Kim Cheng.
She testified last August that she had rented out her house at Paya Lebar Crescent to Chng's mother, Ms Chng Leng Khim, and her three children from Feb 1, 2013 to Jan 31 last year.
She said the Chngs failed to pay their rent of $1,500 a month after March 2013, and this led to a tiff between her and them. Chng is accused of verbally threatening to ruin Madam Khoo and her family members on May 2, 2013.