The video was recorded May 22. It shows a woman walking through knee-deep water and reportedly trying to feed the monkeys junk food.
The zoo's director described what the woman did as "stupid." A spokesman for the El Paso Police Department said what she did was "absolutely moronic and illegal behavior."
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"These are primates we're talking about, they could do some substantial damage to you," zookeeper Mason Kleist said. "They may be small monkeys but they can take you to the ground if they wanted to."
In addition to putting herself in danger, the zoo said the woman put the monkeys in danger too. They are fed a specialized diet, so giving them a foreign food could have caused significant stomach problems.
The trespassing may also have ruined years of delicate training.
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"It takes years to build trust with these animals and for someone to come in there for five minutes for a video on Instagram or whatever just ruins years of work," Kleist said. "It's going to take a long time to get them back to where they were and training."
Zoo officials said they plan to press charges against the woman. They also will look into installing cameras and modifying the fencing to ensure this never happens again.
As for the woman, she's already lost her job over this.
The Lovett Law Firm identified the woman as one of its litigation assistants in the firm's personal injury division. The firm said it did not condone the woman's actions or have any knowledge of it until the video was publicly released.