Diagnosis Murder - Season 1 Episode 18

While Steve is staking out hit man Bruno, Mark sees him collapse, and quarantines him for the plague – but while the obnoxious virologist says it's from the rodents aboard his cargo ship, it's Mark who smells a rat. After some digging he finds 3 of the crime family's ladies who had a reason to rub Bruno out (tampering with his asthma medication) – so was it (wo)man or beast who killed Bruno?