Updated at 6:51 p.m. ET:

Cpl. Eric Casebolt has resigned from the McKinney, Texas, police department, following actions responding to a party on Friday that police Chief Greg Conley described as "out of control" and "indefensible," the Dallas Morning News reports.

At a press conference Tuesday evening, Conley said the resignation concludes the department's internal investigation but that a criminal investigation is continuing. Charges against an 18-year-old who was the only person arrested at the party will be dropped, the Morning News reports.

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Protesters took to the streets of McKinney, Texas, Monday night, marching in the suburb north of Dallas where the local police department's response to a pool party has been widely criticized.

The protest came after the town's police department said that it is investigating Friday's incident — and that Cpl. Eric Casebolt, who forced a teenage girl to the ground and also briefly drew his gun, is on administrative leave.

"I know all of these kids. Most of them are my clients," local barber Lashadion Anthony said at the rally, reports member station KERA. "This is not a race issue. This is a compassion issue. This is the people versus the police. This is the people versus people that have power to do what they want to do."

Resident Laurie Anderson, who spoke to KERA's Stella Chavez as she watched protesters march through her neighborhood, said that the initial incident has taken on a new life.

"I think a sad situation has been completely taken out of context. Things got out of control," she says, "and now it's become this incredibly racial conflict."

Brandon Brooks, 15, the partygoer who shot the video recording of Casebolt shouting profanities and running around as he gave orders, says other police officers at the scene acted professionally.

Brooks tells local Fox 4 TV News that while he was largely left alone, Casebolt was "just putting random black kids on the ground."

"I was like one of the few Caucasian people at the party," he says, "so I think it might have had something to do with racism."

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