The suburban Dallas police officer placed on leave after drawing a gun on teenagers at a pool party has resigned, sources told NBC News Tuesday evening. Cpl. Eric Casebolt of the McKinney Police Department turned in his badge amid an ongoing internal investigation of Friday's escalating incident, which was caught on camera. "He resigned on his own will," McKinney Police Chief Greg Conley said later at a news conference, adding that the 10-year veteran is still entitled to his pension and benefits. Read more at NBC Dallas-Fort Worth He blasted Casebolt's actions at the Craig Ranch North Community pool as "indefensible." He was one of a dozen police officers who were called to the scene for reports of teens fighting. One video shows an officer — later identified as Casebolt — wrestling a 15-year-old girl in a bikini to the ground and using his knees to pin her. He also points his gun at the teens and curses, the footage shows. Conley said some in the large crowd were refusing to comply with orders. Still, 11 of the 12 officers there responded "properly," he added. Related: McKinney Fights Charges of Racism Brought on by Pool Party Video "We as a department are held at a higher standard of action as we do our jobs," Conley told reporters. "I support the fine men and women of the McKinney Police Department who day in and day out do an outstanding job." Related: McKinney, Texas, Cop Placed on Leave The incident has riled up the small city of McKinney after witnesses said officers appeared to be targeting black attendees at the pool party. While some residents told NBC News they worry about racial profiling, others downplayed the incident's racial undertones in a largely integrated neighborhood. City officials and community leaders have since met and called for calm while the investigation continues. McKinney Mayor Brian Loughmiller on Tuesday declined to comment on any possible criminal charges against Casebolt. "Our expectations is that all city employees act professionally with an attitude of service to our community," he said.