SOUTH SACRAMENTO (CBS13) – A killer who gunned down an 18-year-old Sacramento State student in a South Sacramento cemetery last week is still on the loose.

“She smiled all the time. When people say her smile lit up a room, it is not an overstatement,” said older sister Toniesha Bostic.

Bostic said she is still trying to process the loss of her little sister Zarrie Allen after Sacramento police say she was shot and killed in a drive-by while visiting the gravesite of her boyfriend at the Sacramento Memorial Lawn on Stockton Boulevard on July 20.

“I’ve gone through all the emotions of anger, rage, disbelief,” Bostic said.

Authorities said Allen wasn’t even the intended target in the shooting. Investigators said they suspect the drive-by-shooting could have been gang-related. Without any information regarding a suspect or motive, Bostic said not knowing makes the heartbreak even stronger.

“It’s hard to know that whoever did it gets to wake up to their family every day,” she said. “That is the hardest part while my sister who didn’t even see this coming had her life robbed from her, had it stolen from her.”

Now, Bostic is pleading for answers hoping anyone with information on who may have killed her sister will come forward.

“Just think if it was your daughter, sister, your mom, your friend and do the right thing,” she said.

Allen had just finished her freshman year at Sac State. The school is offering counseling services for those impacted by this tragedy.