Nick Smith testified in court against the man who was later convicted of stabbing him and killing his mother. (ABC News)

Days after they were grilled in court by the man who made their life hell for years, Nick Smith and Lottie Spencer say justice prevailed.

"He didn't break me," Nick Smith told "20/20's" Chris Cuomo after the conviction of Waseem Daker, who was tried last month for the 1995 murder of Smith's mother, Karmen, and stabbing Smith 18 times when he was just 5 years old.

In court, Daker served as his own attorney, cross-examining both Smith and Spencer, Karmen Smith's good friend who lived upstairs from the Smiths.

Daker is believed to have committed the crimes as revenge against Spencer. Before being tried for the Karmen Smith murder, Daker spent 10 years in prison for stalking Spencer.

Spencer, who endured hours of questioning by Daker, said she was inspired by Nick Smith.

"I just kept on thinking, that poor Nick has got to confront the man that stabbed him eighteen times, and murdered his mom," she told Cuomo. "And if he's going to do it, I gotta be strong for him, to show him that we can do it."

On the stand, Spencer broke down sobbing after Daker called her testimony "inappropriate."

"It's really inappropriate that you stalk me and harass me, and you're sitting here asking me questions, and I have to come back with you and answer your questions, that's hard for me!" she said.

During his time on the stand, Nick Smith shot back after Daker asked if Smith remembered saying in 1995 that his attacker's eyes were blue.

"I was in the hospital and had gotten stabbed repeatedly by you, so I don't really think that that was a very good time to be asking a 5-year-old questions like that," he said.

A jury convicted Daker last week and on Monday, he was sentenced to life in prison plus 47 years. During his sentencing, he maintained his innocence.

Smith, meanwhile, says he sleeps much easier now.

"I just feel a little more free than I did before," he said.

Watch the full story on "20/20? Friday at 10 p.m. ET.