The trouble for Brandon Ruff started Aug. 3, when he walked into the 35th Police District station on North Broad Street with a bag that contained three handguns and said his name was Ryan Jones.

Ruff, a 28-year-old sergeant in the 16th District, told police that the weapons belonged to a relative. He thought he could anonymously surrender the guns without question.

On Monday, Ruff, an eight-year veteran, was arrested and charged with giving a false identity to law enforcement officials. He has been suspended from the force for 30 days and Police Commissioner Charles H. Ramsey said he intends to dismiss him.

The three guns were traced to different owners, according to the District Attorney's Office. One was reported stolen in South Philadelphia in 2010.

On Aug. 3, Ruff was off duty and wearing civilian clothes. Police were suspicious when they saw he was carrying a weapon, which was found to be his own, and he failed to show documents identifying himself. Not until Ruff was then searched, the District Attorney's Office said, did police realize he was one of them.

"Anyone who is turning weapons in has to show proof of ID," said Officer Christine O'Brien, a police spokeswoman. A no-questions-asked buyback program ended in November 2013.

Ruff sued the Police Department three weeks after the incident, saying the officers had falsely arrested and assaulted him.

Ruff's lawsuit lists seven officers as defendants, and contends that they responded with hostility even after he provided a "call sign" to indicate he was an officer and that they threatened him with Tasers outside the station.

"This is a classic First Amendment retaliation," his lawyer, Michael Pileggi, said. "He spoke out; he was reassigned and put on desk duty. And now, months later, he's arrested."

Pileggi acknowledged that Ruff could have handled the situation better, but said he believed the officers' response excessive. He also described his client as a "decorated officer" without past problems.

Ruff was the subject of at least two Internal Affairs police-involved shooting investigations since 2007, according to documents obtained by The Inquirer. One found that Ruff was in violation when he fired 11 times at a moving vehicle in 2009.

He was cleared of any wrongdoing in a 2007 investigation.

Pileggi said his client just wanted three guns off the street.

"It wasn't criminal," Pileggi said. "His heart was in the right place. He could have thrown them in the river. I don't understand the actions of the city."

Internal Affairs officials did not return requests for comment Monday.