A Springfield police officer has mocked the anti-racism demonstrators who were run down during a white supremacist rally in Charlottesville, Virginia on Saturday, applauding the fatal crash in a Facebook post.

"Hahahaha love this, maybe people shouldn't block roads," wrote Conrad Lariviere in a comment on a news article about the crash.

Lariviere confirmed that he is a patrolman in a Facebook conversation with MassLive, and expressed remorse for what he described as "a stupid comment about people blocking streets."

"Never would I want someone to get murdered. I am not a racist and don't believe in what any of those protesters are doing," Lariviere told MassLive. "I'm a good man who made a stupid comment and would just like to be left alone."

Springfield Police Commissioner John Barbieri said the department has launched an investigation into the comments. He confirmed that an officer named Conrad Lariviere is employed by the department.

"I received notification of this Facebook post earlier today via email from a complainant. The post is purportedly from Springfield police officer. I took immediate steps to initiate a prompt and thorough internal investigation," Barbieri wrote in an email. "If in fact this post did originate from an officer employed with the Springfield Police Department, this matter will be reviewed by the Community Police Hearings Board for further action."

Videos from the protest, which saw neo-Nazi, white supremacist and right wing groups face off against leftist and antifascist demonstrators over the planned removal of Charlottesville's Robert E. Lee statue, show scenes of carnage and panic as a car plowed into antiracist demonstrators.

The videos show a gray Dodge Challenger drive down a clear section of street and crash, without any sign of braking, into a crowd of protesters and two other vehicles. The Challenger then reverses away from the scene of the crash.

Heather Heyer, a 32-year-old Charlottesville paralegal, was killed in the crash, and 19 other people were injured.

Later, police arrested James Alex Fields Jr., 20, of Ohio, and charged him with second degree murder, malicious wounding and failing to stop at an accident that resulted in death.

The original post including Lariviere's comments has since been deleted, but MassLive reviewed multiple screenshots of the comments and confirmed their contents with people who viewed the exchange.

In another comment on the Facebook post, Larivere expressed doubt that the driver, who at the time had not been identified, was a Nazi.

"How do you know he was a nazi scumbag?" Lariviere wrote. "Stop being part of the problem."

But Fields was photographed at the rally carrying the wooden shield of Vanguard America, a white supremacist organization that bills itself on Twitter as "the face of American fascism." And one of Fields' high school teachers told the Washington Post Fields was a white supremacist and appeared fascinated with Nazism as a teenager.

Lariviere berated another Facebook commenter who criticized his post.

"I've been hit by a shitbag with warrants but who cares right you ignorant brat live in a fantasy land with the rest of America while I deal with the real danger," he wrote.

Earlier on Sunday, Springfield Mayor Domenic Sarno released a statement condemning the violence in Charlottesville.

"My thoughts and prayers go out to all those families that suffered a terrible loss of life and were injured. These actions by white supremacists - the 'new KKK' groups - should be denounced by all," he said. "Don't be fooled by their propaganda, once again, they spew hate and enjoy violence. In the end, they will not prevail and good will overcome evil."

Shortly after 9 p.m., Sarno released a statement condemning Lariviere's comments.

"I just got done issuing a statement this morning on how upsetting the tragic incidents were in Charlottesville, Virginia and one of our own officers does this? Unbelievable! There is no place for this in our society, let alone from a Springfield Police Officer," Sarno said. "I stand by and commend Commissioner John Barbieri's steps for a thorough internal investigation and review by our Community Police Hearing Board to pursue the appropriate discipline against said officer."

Correction: The car involved in the crash was a Dodge Challenger, not a Dodge Charger.