A fourth person has been charged in what prosecutors say was a massive counterfeit THC vape cartridge operation run out of a Kenosha County condominium and a Union Grove real estate office.

Prosecutors charged Hannah Curty, 19, of Racine with manufacturing more than 10,000 grams of THC, as a party to a crime. She appeared in Kenosha County Circuit Court for the first time Thursday.

Curty, a University of Wisconsin-Milwaukee student, worked filling vape cartridges with THC oil “on a regular basis” from July to September at two locations, two confidential informants told police.

She is the first person accused of being an employee of Jacob and Tyler Huffhines, brothers prosecutors say are at the center of the vape cartridge operation.

According to a complaint, employees working out of a condo in the Village of Bristol that Tyler Huffhines acquired in early August for the operation cranked out 3,000 to 5,000 counterfeit vaping cartridges each day. They were packaged in boxes with labeling that included candy-like names and wording suggesting the THC content was minimal.

Instead, the cartridges contained as much as 1,000 milligrams of THC — more than 150 times what the label indicated, authorities said.

In Bristol, investigators seized about 31,200 vape cartridges filled with THC, about 98,000 empty vape cartridges, 57 mason jars filled with THC oil, three money counting machines, thousands of empty vape cartridge boxes and packaging, and drug paraphernalia.

The seized THC products have a street value totaling more than $1.5 million, officials say.

Jacob and Tyler Huffhines’ mother, Courtney Huffhines, was charged Tuesday in the operation as well. She posted her $100,000 cash bond Wednesday, according to online court records.

The complaint filed against Courtney Huffhines alleges that the vape cartridges were made in her real estate offices for two to four weeks before being moved elsewhere temporarily and eventually to the Bristol condo.

According to a criminal complaint, Curty worked filling cartridges in both Courtney Huffhines’ office in July as well as the Bristol condo in August and September.

Kenosha County Circuit Court Commissioner Loren Keating set Curty’s bond at $10,000 and ordered she avoid contact with the Huffhines and not possess controlled substances.

Mary Spicuzza, Raquel Rutledge and Meg Jones of the Journal Sentinel staff contributed to this report.

Contact Sophie Carson at (414) 223-5512 or scarson@gannett.com. Follow her on Twitter at @SCarson_News.