Authorities in Northern California are investigating nearly half a dozen attacks against Muslims and Islamic institutions in the last month.
"It seems like every few days there's a vandalism or attempted firebombing of a mosque nationally," said Basim Elkarra, executive director for Sacramento Valley's Council on American-Islamic Relations.
Elkarra says recent incidents in Tracy, Richmond, Santa Clara and Castro Valley are part an alarming trend; that includes more than 50 suspected hate crimes against Muslims across the country in just the last month.
He blames the 2016 presidential candidates: "The recent spike in hate incidents has been unprecedented and we feel it's due to the political rhetoric in the campaign."
Most recently, Donald Trump has called for a "total and complete shutdown of Muslims entering the United States." The candidate has also said that he would increase the surveillance of mosques "because something is happening in there. Man, there's anger, and we have to know about it." Marco Rubio also called for a ban on immigration from "that part of the world" and said that "there is no evidence in this country that there’s widespread and systemic discrimination."
Some law enforcement officers agree that these statements have influence.
Jeffrey Harp recently retired as second-in-command of the San Francisco office of the FBI, which investigates such crimes. He compares the impact of such messages with that of Southern officials who rejected integration a half-century ago.
"You're going to have people who are watching those candidates who say, well, these are supposedly leaders in our nation and they're going to think those people are the gospel," Harp said.
Harp said the FBI works with local law enforcement and civil rights groups to try to prevent such crimes, but often it's public tips that make the difference. Recently, a Richmond man allegedly made criminal threats against Muslims and posted a picture of what appeared to be a pipe bomb online. In that case, a Facebook friend reportedly alerted authorities.
Franklin Zimring, director of criminal justice at UC Berkeley's School of Law, says that local law enforcement should look for the "usual suspects" when investigating hate crimes.
"If you're a police officer there, and there's a brick through a Muslim house of worship, then what you have to do is round up the usual suspects. They're the same people who drink too many beers in bars and will in other situations go off gay-bashing or finding themselves racial minorities," he said. "Those are essentially thugs taking on different targets because Muslims are in the news."