Graffiti threatened to mar a Sunday morning mass for the families of fallen Chicago Police officers.

But the red spray-painted graffiti on the Gold Star Families Memorial near Soldier Field was removed by city workers before the service.

Now the Chicago Police Memorial Foundation is offering $3,000 for information leading to the arrest of the vandal, whose graffiti was discovered Thursday night on a concrete wall north of the memorial.

“It’s just despicable,” said former police Supt. Phil Cline, head of the foundation.

Fraternal Order of Police spokesman Pat Camden said the graffiti didn’t mention the police. Police Supt. Garry McCarthy said he believes it was the work of juveniles.

Chicago Police Sgt. Brian Hauser and his family attended the mass with about 150 other people. His father, Chicago Police Officer Gregory Hauser, was 43 when he and his partner were fatally shot on May 13, 2000 — Mother’s Day.

They were responding to an argument between a man and his grandmother. The man, Roman Chavez, disarmed Hauser and killed the officers.

“We all have something in common,” Hauser said of the families at Sunday’s mass. “We’ve all gone through holidays without them [the fallen officers]. This is like our other family.”

Contributing: Hunter Clauss