User blog comment:MarleneZ./How Are We Doing?/@comment-24.45.42.54-20140413015427/@comment-86.183.12.43-20150410163318

All 4 wouldn't. However there is a possibility that L and Light would, since light wanted to join the police force. Obviously L and Mello crossed paths, as he is L's successor and L had recounted the BB murder cases to him. Mello and Near grew up together and competed to become L, so it's pretty obvious they crossed paths. Near being ranked first at Wammy's has probably also met L.