After Learning New Things About Nicole Brown Simpson, Sister Tanya Brown ‘Feels Like I’m Grieving for the First Time’

Tanya Brown spent lots of time with sister Nicole Brown Simpson over the years, but since Tanya was so much younger, there was still a lot she didn’t know about her when Nicole was killed in 1994.

“People don’t always understand, but I’m 10 years younger than Nicole,” Tanya tells PEOPLE. “She left the house when I was 7 or 8 years old. I missed out on so much of her life because I was in junior high, high school, and college by the time she was married and started having kids.”

Nicole was just 35 when she was murdered in June 1994 on the walkway to her Brentwood, Calif., condo, allegedly by her ex-husband, NFL legend O.J. Simpson. Her friend Ronald Goldman, 25, who had stopped by her house to return reading glasses her mother had left behind at the restaurant where he worked, was also killed.

“We all know about the abuse,” says Tanya. “We all know what she went through with Simpson. But who really knew Nicole? Who was Nicole?”

Tanya, who has spent the last 32 years trying to find out more about her sister, was taken aback when she saw the PEOPLE App interview with Joseph Perrulli about his new memoir, The Forgotten Briefcase, about his relationship with Nicole in 1992 after she separated from O.J.