Benjamin Crump flew into Dallas Friday morning and made the 45 minute drive north to McKinney's police headquarters. The Florida based attorney says he came to Texas to get answers.

"What we really need is information," Crump said.

Crump, who has represented the families of Trayvon Martin and Tamir Rice in the past, stood by three teens who were at the center of a viral video at a McKinney pool party back in 2015. Four more teenagers now plan to join a lawsuit filed in January by the 15-year-old girl at the center of the video and Crump intends to help.

"McKinney has become the ground zero for the fight against police brutality against young people of color," Crump said.

The teens and their attorneys contend Officer Eric Casebolt, the city of McKinney and the McKinney police department violated their constitutional rights during the altercation that was caught on cell phone video. The video showed Casebolt, who resigned shortly after the video was released, throwing one young woman to the ground and drew his gun while running after another group of teens.

"You can't put it on the children. The responsibility lies with the trained professional with a badge and a gun," Crump said.

Crump joined Kim T. Cole, a Dallas based attorney who helped file the original suit. She says her team has repeatedly asked for personnel files relating to Officer Casebolt and any information on the investigation into the altercation. She says her requests have been repeatedly declined.

"This is about transparency and accountability," Cole said.

WFAA also requested information on Casebolt's history in 2015 and again Friday. Both times the city declined to answer instead sending this statement.

"The City of McKinney denies the claims alleged against it and the McKinney Police Department, and as such, will vigorously defend the filed lawsuit. McKinney prides itself in cultivating the highest standards of training and professionalism for our officers, and it strongly believes that its standards and training will withstand legal challenge."

Attorneys say they've heard from other former officers who say Casebolt had a history of complaints against him and issues with his training. They say more information will come out shortly on those claims.

Crump says the other teens will join the lawsuit in the next few months, he's hoping to get more information on Casebolt before filing.