A STUDENT murdered the uni roommate she described as her "best friend" in a bloody butcher knife rampage, police say.

Luisa Cutting, 21, stabbed Alexa Cannon up to 40 times at the apartment they shared in Radford City, Virginia, according to authorities.

In a chilling social media post before they moved in together, Alexa wrote: "Pray that we don’t kill each other this year."

Officers responding to the horrific scene are said to have found 20-year-old Alexa's blood-soaked body - with a knife sticking out of her mouth.

They were called at around 7:45am on Thursday - with a police dispatcher saying she heard someone shouting about a knife, according to a search warrant obtained by the Roanoke Times.

When cops arrived at the off-campus apartment they allegedly saw Cutting covered in blood.

She is then said to have told police: "Arrest me - I killed her".

An alleged motive has not yet been made clear.

CLOSE FRIENDS
Posts on psychology student Alexa's social media pages suggested that the pair had a close relationship.

She wrote about Cutting on Instagram in March: "I met this girl two years ago online and somehow we ended up living across from each other for a year, this summer she was equivalent to my mom in Cancun.

"And unimaginably she still puts up with me and now we’re living together next year.

"Love you more Lu and everyone pray that we don’t kill each other this year."

A post on Alexa's Facebook page from July read: “So incredibly proud of my best friend, Luisa Cutting for becoming Latinos Student Alliance’s President!

"I know you’re going to be amazing with everything you do! Love you more!!”

Cutting replied: “Love you so so much."

Cutting is on interim suspension at the from Radford University as she faces a murder charge - the first in the 17,000-population town in eight years.

Brian Hemphill, Radford University president, said: "This is a tragic moment for our campus community and the Radford family.

"During this difficult time, we ask that you provide support to your fellow Highlanders.

“The days and months to come will also be difficult as we extend our deepest sympathies, as well as our thoughts and prayers, to the family and loved ones of our student."