SAN FRANCISCO (CBS SF) — It’s something that haunts Tess Fitts. Where is her tiny niece Arianna Fitts, who has been missing since her sister, Nicole, was murdered five years ago in San Francisco?

On Thursday, the FBI released an undated sketch of what Arianna would look like today, hoping it will generate leads as to where the little girl may be.

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Tess Fitts says she prays that Arianna is still alive.

“There is no way I ever thought it take five years to find her,” Fitts said “I absolutely still remain hopeful. I do believe that she is alive and out there. Someone knows where she is.”

There are lots of unanswered questions surrounding the 2016 murder of Nicole Fitts and the disappearance of Arianna. While continuing their investigation in the San Francisco Bay Area, authorities are also turning their attentions to Los Angeles. They believe witnesses may have moved there over the last 5 years.

The FBI told CBS Los Angeles that they have some leads, but would not go into detail as not to jeopardize the case.

Tess Fitts said there was no question in her mind that the murder and disappearance were related.

“For that to happen to her, along with her kid being gone, there’s just no way that it’s not related,” she said.

Nicole Fitts remains were discovered in San Francisco’s McLaren Park by city workers on April 8, 2016, buried in a small, shallow grave, curled in the fetal position, and covered with plywood.

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Arianna Fitts, missing after her mother was found killed in San Francisco’s McLaren Park on April 8, 2016 (Photo courtesy of San Francisco police).

The single mother of two daughters was reported missing on April 5. She was last seen on April 1, when she was “summoned to meet a person known to her,” police said at the time without elaborating.

No suspects or persons of interest have ever been named in the case.

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Arianna was last seen in mid-February 2016 and investigators believe she was staying with friends or babysitters.

Police have offered a $100,000 reward for information leading to the arrest and conviction of those responsible for the murder of Nicole Fitts and Arianna’s disappearance. In addition, Nicole Fitts’ former employer Best Buy has also provided a $10,000 reward for information to help find Arianna.

“The San Francisco Police Department continues to actively investigate this incident and we will continue to investigate this matter as long as it takes. We will pursue all leads, continue to examine all evidence, and seek out all individuals who may have information,” police said in a statement on Thursday.

“We wanted to speak to everyone who interacted with Nicole leading up to her disappearance. Try to remember every detail you can, no matter how insignificant you think it may be. If you remember something, please contact us even if you previously talked with us,” police said.

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Anyone with information about the homicide or with information on Arianna’s whereabouts is urged to call the Police Department’s anonymous tip line at (415) 575-4444 or to text a tip to TIP411 with “SFPD” at the start of the message.