CHICAGO (AP) — As damning as video evidence in the George Floyd case appears to be, prosecutors know they must bring the right charges underpinned by sound legal logic if they hope to convict a Minnesota officer for killing Floyd. Exhibit No. 1 at trial is likely to be video showing Officer Derek Chauvin pressing his knee into the back of Floyd’s neck on May 25 as a handcuffed Floyd says he can’t breathe. But strong video evidence doesn’t mean a conviction will be easy. Legal experts say defense lawyers likely will try to raise doubts about whether Chauvin’s restraint killed Floyd or existing health conditions did.