Happening now hours after America's latest shooting rampage, police are trying to figure

out why a gunman opened fire at Michigan State University.

Three students are dead, five are wounded as new information is emerging about the now

deceased shooter and the note he left behind.

Also tonight, the White House reveals its leading theory that the three mysterious objects shot down by U.S. fighter jets were, quote, benign.

Senators have now been briefed on the downed objects, as many Americans questions about what happened remain unanswered.

And Nicky Haley makes it official, becoming the first Republican to challenge Donald Trump for

the GOP presidential nomination in 2024.

We are breaking down the early race as Trump braces for more

former allies to run against him. Welcome to our viewers in the United States

and around the world. Wolf Blitzer is off today. I'm'm Brianna Keeler and you're in the situation room. We do begin with the investigation into the mass shooting in Michigan and the

heartbreaking loss being felt by a tight-knit college community.

CNN's Adrian Brodiss is in East Lansing tonight.

You know, you're going to be multiple, multiple

Illinois.

Tonight, investigators searching for a motive after shootings at Michigan State University left three students dead.

Ari L Anderson, Brian Frazier, and Alexandria Werner.

Five others were critically entered.

The gunman, 43 year old Anthony McRae, first opened fire on the

campus Monday just before 8.30 PM. Oh my God. There's still people down there

trying to get out. Shooting at two locations, the first inside a classroom at Berkey Hall.

While the officers were managing that scene at Berkey Hall,

...