Denise Brown likes to remember the little things about her sister.

Like the way Nicole Brown -- who was once married to O.J. Simpson but was murdered in 1994 -- always had french fries or another snack in the front seat of the car in case one of her kids got hungry. Or what a great mother she was.

"She was just a normal, down-to-earth human," Denise said.

She had no idea that her sister was living in "hell," as Denise put it, until months after her death when she began to read Nicole's diaries and understand the cycle of domestic abuse she had lived with for years.

"That's when I realized my sister was living a nightmare," Denise said.

In the years that followed, O.J. Simpson was tried and acquitted in the murders of Nicole Brown and of Ron Goldman, a Buffalo Grove native, but lost a civil suit that awarded $33.5 million in damages to Goldman's family.

The tragedy inspired Denise Brown to become one of the country's most outspoken activists for domestic violence awareness, running the Nicole Brown Foundation and lobbying for the passage of the Violence Against Women Act of 1994. She is the keynote speaker at the WINGS Purple Tie Ball Saturday night at the Westin Hotel in Itasca.

Rebecca Darr, CEO of WINGS, the largest domestic violence housing agency in Illinois, said Denise Brown's openness about what happened to her sister has done a lot of good over the past 20 years.

"I don't think people realize that every time you retell the story of trauma from your past, no matter how long ago it was, it's hard to do," Darr said. "But (she) continues to do it over and over again to benefit others, educate others about a serious issue and prevent other families from going through what (she) did."

Once she began to understand more about domestic violence, Denise Brown said she realized there were signs in her sister's marriage that she could have noticed all along, such as verbal abuse and a physical fight that led them to take Nicole to a hotel for a night. She said the couple made up the next day and Brown believed her sister's reassurances, not understanding the cycle of domestic violence or how much danger her sister could be in, even after her divorce.

"It was her silent hell she was living in," Brown said.

In 2008, O.J. Simpson was sentenced to prison on robbery charges, and Brown said it wasn't until that moment when she felt she could let go of her anger.

"When he was thrown in jail, that's when I was able to start moving my life forward. It took a long time, but that's when I could breathe again," she said.

Over the past two decades, Brown says society has come a long way in terms of people being aware of domestic violence and being more comfortable talking about it, but there is still a long way to go.

"People used to think this only happened to poor people or homeless people," Brown said. "Nicole was not poor or homeless. It can happen to anyone."

Denise said she has gone through different stages of her grief for her sister, but it never gets easier.

"When I remember certain things, I still cry," Brown said.

That's why she chose not to watch the documentary or TV series that came out this year about the O.J. trial.

"I lived it. I don't need to go there," she said. "When I talk about Nicole I go back there; I revisit it every day."

The highly acclaimed television projects have put the high-profile case back in the news, which has been both good and bad, Brown said.

"It's a Catch-22. I love it and I hate it. I hate it because it brings back all of this stuff, but I love it because it brings awareness to domestic violence," Brown said. "Is it fun to relive, no. But there is hope. There is light at the end of the tunnel and people can see they don't have to become another Nicole."

• WINGS operates a 24-hour hotline at (847) 221-5680 for anyone needing domestic violence services, or knowing of someone who does.