MINNEAPOLIS (WCCO) — A series of brazen robberies by suspects you might not expect has caused police to issue a crime alert on the University of Minnesota campus.

There’s been a total of four robberies in the past couple weeks near the campus.

Police say they believe in two of the cases, a pair of teenage girls are responsible for assaulting students in an attempt to steal their cell phones.

Eighteen-year-old Odessa Richmond was booked at Hennepin County Jail last weekend.

The other girl’s name isn’t being released because she’s not eighteen.

University of Minnesota student Katie Johnson said after her car was recently broken into in this area, she started to get crime alerts texted to her.

“Well, I live two blocks from here, and this is where it happened, so really close,” Johnson said.

She couldn’t believe when she saw a pair of teen girls were partly responsible for recent robberies on campus.

“It’s just really scary,” she said. “Usually it’s a male-oriented crime, so it certainly shocked us when we saw that.”

The first robbery involving the teen girls happened around 10th Avenue and University Avenue, late in the evening on Oct. 20.

“They were going after iPhones and they would approach students and ask to use their phone, and when the students refuse, they would up the issue and eventually assault them and steal their phones,” said Deputy Chief Chuck Miner

of the U of M Police Department.

Police say the robbers went as far as grabbing a plastic chair to hit the victim. A week later, police think the girls were at it again. This time, in broad daylight on the corner of 15th and University Avenue Southeast.

“It occurred in a very populated area, near a bus stop, in fact,” Deputy Miner said. “A bunch of citizens got off the bus, saw what was happening, intervened, helped stop the assault and the robbery.”

The two were caught by police a few buildings away. Police say they caution everyone on campus to not give up their cell phones to strangers.

“If it’s an emergency, you can offer, ‘I can call 911 for you, if this is an emergency, I can maybe call somebody for you’ but just don’t give it up,” he said.

It’s a lesson the recent crime alerts seem to be reinforcing.

“If someone were to ask me now, I probably wouldn’t let them but before I definitely would have let someone always use my cell phone,” Johnson said.

Richmond was also arrested a couple weeks ago for a robbery in Bloomington.

Police say they recommend all students walk in groups late at night or call the U of M’s free escort service.