Sarah and jane were playing basketball. they collided and fell. sarah’s knee was lightly bruised. jane’s elbow was scratched, causing a little blood to ooze out. after a few days, jane observed pus formation around the scratch on her elbow, while sarah’s knee was fine. the pus formation on jane’s elbow is a result of . the receptors on the sensed the pain that jane experienced

Cold case files recently began re-investigating an old murder case. the murder took place in the park; a young man, james, was hit over the head with a brick and killed. police suspected the jealous former boyfriend of james' wife, karen. whoever killed james may have washed their hands in a near-by bird bath as detectives found blood in the bird bath. since the murder took place before dna fingerprinting was available, the suspected killer, ronnie, went free. detectives are now reviewing the blood evidence using dna fingerprinting. based on the dna fingerprints of all possible suspects, who is james' killer?