SEATTLE — A teenager rode her bicycle through a mall parking lot when an off-duty officer working for a private security company pulled her down, threw her to the ground and shocked her with a stun gun.

Caught on surveillance video , the 2014 encounter with the girl, who is black, drew outrage. She initially was charged with assaulting an officer before the case was dropped. Now, she’s targeting his Washington state police department in a newly expanded lawsuit.

It claims the Tacoma department’s policies lead officers to attack residents, including minors such Monique Tillman, then 15, and violate their civil rights. Police supervisors routinely approve “abusive, excessive and unnecessary uses of force” and retain abusive officers, according to the expanded suit filed last week.

The original claim targeted Officer Jared Williams, who is white; the mall’s owner; and the security company. It grew to include the department after it acknowledged that the officer acted within the scope of his police duties despite being paid by a private employer, said Tillman’s lawyer, Vito de la Cruz.

The lawsuit has not affected the department’s policy of allowing officers to work for outside companies, a police spokeswoman said Tuesday. Off-duty officers wear their uniforms on those jobs and are officially police while they work private security or an event, she said.