A woman was critically injured in a stabbing around 9:15 Monday morning at the Fifth Avenue Apartments near 25th and Douglas.   

Police say a man and his sister took in a homeless man they knew last night. This morning they say he started acting erratically and was asked to leave.   

Police say that's when 20-year-old Dmitry Vanderbeek grabbed a kitchen knife and cut the siblings.  

The woman, 28 year old Lucia Francisco-Simon, was taken to the hospital in critical condition with a stab wound to the back of her neck.  She is expected to survive.

Her brother, 33 year old Jacob Francisco, was treated at the scene.  Vanderbeek was booked for two counts of felony assault and use of a weapon to commit a felony.