WESTBROOK — Police on Monday arrested a Westbrook man who allegedly shot a gun at a cab driver Sunday night following an altercation on Carlson Street.

Keith W. O’Brien, 30, is charged with criminal threatening with a dangerous weapon, aggravated reckless conduct with a dangerous weapon and falsifying physical evidence, according to a release from Westbrook Police Capt. Michael Nugent.

The driver of the cab allegedly told police that while he was driving a man and woman to a Westbrook home, the man threatened him and “made disparaging comments about his ethnicity” before getting out of the cab and smashing the windshield.

The driver called police, then followed the couple on foot to a Carlson Street home, according to Nugent. The man, since identified as O’Brien, then allegedly came back outside and fired a gun at the driver.

Police did not release the name of the cab driver or the name of the cab company.

After conducting interviews and executing a search warrant at the Carlson Street home, police arrested O’Brien early Monday morning. Police allegedly discovered evidence including ammunition, Nugent said.

O’Brien was released from Cumberland County Jail at about 10 a.m. Monday, according to a jail official. Neither the amount of his bail nor a court date was immediately available.