WATCH: Woman steals Holocaust survivor's diamond necklace, ring off her body

LOS ANGELES - A 99-year-old Holocaust survivor is a recent victim of a possible crime spree targeting seniors.

What we know:

A few months ago, Abe Knobel's mother was home near Beverly Hills with a caretaker, getting ready to leave for a family get-together, when a woman approached and offered to help carry the 99-year-old’s wheelchair.

"[The stranger] then proceeds to give my mom a necklace," said Knobel. "A phony necklace.  While she does that, she removes my mom’s necklace without her knowing about it."

In the surveillance video shared with FOX 11, the thief appears to tell the caretaker to go outside for more jewelry that will be gifted to her. Then, the crook grabs the 99-year-old’s diamond ring and leaves. In the video, you can hear the 99-year-old sound frustrated and confused, telling the caretaker what happened.

What they're saying:

"It’s just terrible," said Knobel. "It’s the worst of humanity. How can someone take advantage of the elderly in such a manner?"

Knobel said he saw a news report from FOX 11 that aired Tuesday night, about thieves in the San Fernando Valley targeting seniors and jewelry. He contacted us saying it also happened to his mother in her home near Beverly Hills, but isn’t sure if it’s the same suspect.

"I definitely want to warn people," said Knobel. "This is something that people just need to be aware of."

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Knobel called it a "racket. They make it seem like they’re familiar to the person they’re about to rob. Before [the victims] know what’s going on, they’re gone."

Knobel estimates the stolen diamond necklace and ring to be worth about $35,000.

FOX 11 reached out to the Los Angeles Police Department about this case, as well as the possible crime trend, but so far we haven’t heard back.

"I’m just hoping police can do something about this," said Knobel.