From [NBC] A white Prince George's County police officer accused of attacking a black, off-duty Colmar Manor police officer has lost a civil lawsuit, and Prince George's County is expected to pay $31,500 in damages.

News4 has learned that last week a jury found Officer Matthew Waisempacker liable for violating the off-duty officer's constitutional rights and using excessive force.

The two men clashed at a pool party in July 2015 in Fort Washington, overlooking National Harbor. Neighbors complained about noise, and Prince George's officers responded.

Cellphone video obtained by News4 shows the uproar. A man can be heard saying, "I told you I was an officer."

The man who hosted the pool party said Waisempacker lashed out after the off-duty officer said he was an officer and that he was armed.

"He did identify himself as a police officer, and he told them he had a gun, and what happened was this white officer just went ballistic -- forcing him down to the ground. They wrestled him outside and just threw him down," the resident said. He asked News4 not to identify him.

Photos used in court show the off-duty officer's deep purple bruises.

Attorneys Darrell Robinson and Perry Paylor, who represented the off-duty officer, said their client is still suffering. The jury took into consideration "humiliation and embarrassment," Robinson said.

The Colmar Manor officer no longer works for the department, the department confirmed.

The Prince George's County Police Department said Waisempacker has worked for the department for six years. They declined to comment on the case because they said it is ongoing.