SAN FRANCISCO (KRON) — An unsettling week for students in the Bay Area, as there have been at least four incidents of violent threats against students and schools just this week.

Some arrests have been made and some investigations are ongoing.

And on Thursday, KRON4’s Gabe Slate talks to an expert about why kids make these violent threats.

Santa Rosa police released a graphic picture on Thursday depicting a young woman with an assault rifle, claiming to be a school shooter with the warning to avoid a Santa Rosa High School.

The picture was floating around social media police are looking into it.

Police believe it may be related to the violent threat found on a bathroom wall at Santa Rosa High School that lead to over 1,000 kids being sent home early and the arrest of a 16-year-old student believed to write the message.

That was just one of four incidents this week in the Bay Area where violent threats were made against a school and its students.

The words “Everyone is Dead” were discovered on a bathroom wall at Alameda High School. It prompted hundreds of students to stay home on Tuesday.

Law enforcement is investigating.

And in San Jose, a threat surfaced on Twitter that some Alum Rock schools would be “shot up.”

At the same time on an unnamed social network, someone threatened violence against Oak Grove schools in San Jose.

Both incidents lead school officials to warn parents. Police are investigating.

And a threat was discovered in San Jose written on a women’s bathroom stall, saying there would be a shooting Wednesday at 5 p.m. on the campus of San Jose State University.

The school sent out phone alerts rattling nerves among the students.

Now, KRON4 met up with the University of San Francisco Professor Kimberly Richman, an expert in criminology and sociology.

KRON4 asked her, assuming it is students making these threats, why do they do them. What is the motivation?

“Kids who are left out, don’t fit in, can feel alienated,” Richman said.

With the tragic high school shooting in Florida that killed 17, which happened before this streak of violent school threats in the Bay Area, KRON4 asked Richman if there is a connection.

When big national school shootings happen, does it inspire others to make threats? She said yes.

“Yes, kids can see these events on the news and relate to the shooter, be inspired and emulate them,” Richman said.