Sean Collier, the MIT campus police officer who was murdered Thursday night, was the brother of Andrew Collier, an employee of Hendrick Motorsports, a prominent NASCAR racing team.

"It's sad," Kasey Kahne, driver of the No. 5 Hendrick car, said following qualifying at Kansas Speedway on Friday. "It's been really crazy. It's sad that it has come to this. We are trying to race, but I was up (Thursday night) until 2-something in the morning, just watching the news, seeing how things were going. It's been sad to pay attention to and to watch. Definitely, thoughts and prayers are with everybody involved."

Sean Collier, police said, was shot by Boston Marathon bombing suspects Tamerlan Tsarnaev and his brother, Dzhokhar.