So now it turns out that the FBI knew all about the accused Boulder shooter, but paid no attention to the obvious warning signs until police say the rabidly anti-American immigrant from Syria murdered 10 U.S. citizens in the supermarket.

“The suspect’s identity,” the New York Times reported, “was known to the FBI because he was linked to another individual under investigation by the bureau, according to law enforcement officials.”

Stop me if you’ve heard this one before.

The Famous But Incompetent FBI likewise knew all about accused shooter Ahmad al-Aliwi Alissa’s fellow Muslim immigrants who committed mass murder, like the Tsarnaev brothers — but did nothing until those welfare-collecting “asylees” blew up the Boston Marathon.

The FBI also had early warnings about the Muslim terrorists who shot up the gay nightclub in Orlando, the Christmas party in San Bernardino, Fort Hood, the cartoon-drawing contest in Texas … and yet the G-men sat on their soft hands until scores of Americans were murdered in cold blood.

But it’s not only foreign Muslim terrorists the FBI can’t be bothered lugging. It’s domestic killers as well.

For instance, in 2018 the FBI’s national tip line got a 13-minute-long earful from the aunt of the Parkland High shooter Nikolas Cruz — but did nothing until 17 people were gunned down.

Remember serial killer Gary Sampson? Before he murdered three innocent men in 2001, he called the FBI office in Boston from a pay phone in Abington and offered to turn himself in on some unsolved bank robberies.

But it was a Friday afternoon, so the FBI “disconnected” his call and didn’t bother to pick him up. The next day, Sampson started his two-state carjacking murder spree.

This is Your FBI, as the old radio show used to begin.

But there have been some cases that the FBI has been on top of:

Lady Gaga’s stolen French bulldogs.

Tom Brady’s purloined football jerseys.

The “noose” on NASCAR driver Bubba Wallace’s garage, which turned out to be a door pull rope. (Fifteen agents were assigned to that “hate crime.”)

Taking a knee en masse for George Floyd.