LOS ANGELES—The delicate, gold-specked mosaic that hangs above the entrance to St. Peter’s Italian Catholic Church on the edge of Chinatown was marred with bright red paint Monday morning in an apparent act of vandalism, officials said. A small crowd had gathered at the building by noon, where detectives investigating the scene said it appeared to be linked to the day’s holidays, which include Indigenous Peoples Day and the former Columbus Day. A fallen banner on the church’s front steps read, “STOP COLONIZING OUR LAND,” while graffiti on the sidewalk spelled out phrases including “Land Back,” “USA” and “Stolen Land.” Explosions of red paint dotted the steps, doors, and walls of the church on North Broadway, which was established in 1904 and holds Masses in English, Spanish and Italian. Arturo Martinez said he first spotted the red paint around 8:15 a.m. on his way into his daughter’s nearby clothing shop. …