The act of vandalism was filmed by Ryan Lutz of Orange, who posted the video on social media after he said Colosseum guards failed to show interest in it.

Italian police said in a statement Thursday that they had used photographic comparisons to identify the man who carved his name and that of his apparent girlfriend on the ancient landmark last week. But beyond saying he was from Britain, the Carabinieri did not name the suspect nor specify his whereabouts.

When reached by phone, police said no further information could be given.

Italian officials have vowed to find and punish the tourist who carved “Ivan+Haley 23” on the Colosseum’s wall, a crime that has resulted in hefty fines in the past.

It was at least the fourth time this year that such graffiti was reported at the Colosseum, an act that carries fines of up to $15,000 and five years in prison.

Lutz, who is on a two-month backpacking trip through Europe, said he had just finished a guided tour of the Colosseum on June 23 when he saw the person “blatantly carving his name” in the Colosseum wall. Lutz told the Associated Press that he took out his phone to film the man because he was so shocked at what he was doing.

“And as you see in the video, I kind of approach him and ask him, dumbfounded at this point, ‘Are you serious? Are you really serious?’” Lutz recalled. “And all he could do is, like, smile at me.”

Lutz, a recent graduate of Cal Poly Pomona, said he tried to get a guard to take action, but neither the guard nor his supervisor did anything, even after Lutz identified the man and offered to share the video.

He said he decided to post the video online the following morning, after he had calmed down. Although Lutz says he appreciates graffiti and art, “carving your name seems like a pretty selfish act.” He said visitors to foreign countries cannot repay their hosts “with blatant disrespect like this.”