That was in stark contrast to the mood on the opposite end of the courtroom, where relatives of the man that Mendez murdered were speaking out.
"For the rest of your life, you will suffer. Your end of this life, you will go to hell," Belal Mohammad Abuawad said directly to his brother's killer, denouncing Mendez for robbing and then shooting 27-year-old Jamie Sharif Mohammad Abuawad in April 2012.
The 23-year-old Mendez rarely made eye contact with his victim's relatives.
Abuawad ran a gold-buying business. He had driven to Mendez's neighborhood thinking that Mendez was a prospective client. Instead, Mendez ambushed him in an alley, shooting him three times and stealing $300 in cash.
Last week, Mendez was convicted of first-degree murder and second-degree robbery. On Tuesday, he was sentenced to life in prison without the possibility of parole, plus 25 years to life.
Judge Ronald Rose said Mendez's actions "were willful and deliberate and premeditated." The judge also ruled that Mendez serve his life sentence in a high security prison.
Mendez has been placed in restraints ever since a courtroom outburst last month when he threw a chair at prosecutor Hilary Williams and LAPD Detective Myra Kellum.
Kellum says the way that Mendez lured his victim to his neighborhood was particularly disturbing.
"This was more premeditated in a sense that he lured the victim to where he was and then carried out his acts," said Kellum.