Oakland A’s fans are ruthless.

On Monday, fans showed up at RingCentral Coliseum to return to “the scene of the crime” in the stands, where a couple allegedly engaged in a sex act the day prior.

A now-viral video shows a group of fans laughing and holding signs that read lewd messages including “Play Balls” and “Don’t Blow It.”

Another sign stated, “Keep your head in the game.”

One person in the clip can be heard saying, “We’re here at the scene of the crime,” before the camera showed the view from the section and fan-crafted signs.

The A’s fans were spotted in what appeared to be the same upper-level section two fans were caught in an alleged rendezvous during Sunday’s 5-3 win against the Mariners. A separate viral video appears to show the couple isolated in the top left corner of section 334.

The Oakland Police Department has since launched an investigation into the matter.

“However, the parties have not been identified and no one has been cited/arrested at this time,” said OPD Public Information Officer Candace Keas in a statement to KRON4. “The violation is 647(a) PC. Lewd acts in public.” 

If charged and convicted, the couple could face up to six months in jail and a fine of $1,000.

The A’s appear to have amped up security in the upper deck, according to a video by Jomboy Media, which showed stadium staff standing at the entrance of each section during the team’s 5-3 loss to the Marlins on Tuesday.

Oakland plays host to Miami to close out their three-game series on Wednesday.