Two people were killed and six others wounded in an unprovoked stabbing rampage Thursday in front of the Wynn Casino on the famed Las Vegas Strip, officials said.They were identified by the medical examiner's office as Brent Allan Hallett, 47, and Maris Mareen Digiovanni, 30, both of Las Vegas, a Clark County spokesman said.The suspect, Yoni Barrios, 32, was booked into the Clark County Detention Center on two counts of open murder with a deadly weapon and six counts of attempted murder with a deadly weapon, police said early Friday.It was too early in the investigation to determine a motive, Koren said, but officials believe the incident was unprovoked."The initial altercation or the initial stabbing occurs on the sidewalk area, appears unprovoked — there is no altercation beforehand," Deputy Police Chief James LaRochelle told reporters."