I just killed someone he's my alibi

You were Matt's best friend. As he usually backed you up for almost everything.... though one day, you called in him a panic. You were stammering and blabbering on about something. He couldn't make out what you were saying

"Hey, calm down...say that again."

He spoke calmly into the phone.... until he heard you KILLED SOMEONE. He sighed suddenly...and replied with a sentence you never thought would come from him...

"Ill be your alibi."