McKINNEY, Texas — A white police officer in suburban Dallas has resigned after he was recorded on video pushing a black teenage girl to the ground outside a pool party and brandishing his gun at other teens.

Officer David Eric Casebolt’s actions were “indefensible,” though he was not pressured to quit, McKinney Police Chief Greg Conley said at a press conference after the officer submitted his resignation.

A teenager at the party posted a video online showing Casebolt’s interactions with the teens as officers responded last Friday to calls about the gathering at a community-owned swimming pool in McKinney. The 41-year-old former Texas state trooper and 10-year veteran of the McKinney force was put on administrative leave after the incident. His lawyer, Jane Bishkin of Dallas, confirmed he had quit the force.

Conley said a review of the video showed that “our policies, our training and our practices do not support his actions.”

Twelve officers responded to the report of fights and a disturbance at the Craig Ranch North Community Pool in an affluent area of McKinney, which is north of Dallas. “Eleven of them performed according to their training,” Conley said. Casebolt did not, he said.

“He came into the call out of control and the video showed he was out of control during the incident,” Conley said.

Casebolt’s actions are under investigation and no decision has been made whether charges will be filed against him, Conley said. Charges of interfering with an officer and evading arrest against the only man arrested during Friday’s incident have been dropped, Conley said. Everyone else detained was released.

Bishkin declined to say where Casebolt is now and said the officer had received death threats. The attorney said she would release more information at a news conference today.

Those who demonstrated this week at a McKinney school compared the city to Baltimore and Ferguson, Missouri.