Authorities intercept 22 letters sent by the UNLV shooting suspect that were addressed to faculty

At a press conference on Thursday, Las Vegas Police Sheriff Kevin McMahill said that shooting suspect, identified as Anthony Polito, mailed 22 envelopes to faculty members across the country with no return address before killing three people and wounding another on the University of Nevada, Las Vegas campus Wednesday. McMahill said authorities recovered the 22 envelopes and the first one that they opened had an unknown white powder in it. McMahill warned anyone in education who receives an envelope that's taped closed with no return address to proceed with caution and contact their local authorities.

Video Transcript

KEVIN MCMAHILL: The suspect's vehicle was recovered at UNLV. And after executing a search warrant, we located a dash Cam in the vehicle, which allowed us to have a better understanding of the suspect's movements earlier in the morning. Our detectives learned prior to the shooting, the suspect had earlier visited a Henderson post office and sent 22 letters to various university personnel across the country with no return address.

We are currently working with the postal inspector and our federal partners to begin processing these letters. We do not know the contents of these letters. And we're working to contact the recipients of those letters.

I learned that in the screening of those envelopes that we were able to intercept after going through 14,000 pieces of mail and identifying the 22 that were sent, the first letter that we opened had an unknown white powder substance in it. Our armor unit and detectives are out currently processing those envelopes. And what we're asking is that if anybody in the education world receives a letter with a no return address that is taped, we ask you to proceed with caution and contact your local authorities particular attention. From the ones that have been addressed are those that Carolina and UNLV.