Spitting of blood or blood-stained sputum from the lungs or bronchial tubes is a symptoms of

Bronchiectasis

Explanation:

Bronchiectasis occurs when a person have a severe infection that causes the walls of the airway thicken and accumulate much mucus, and the symptoms includes Spitting of blood or blood-stained sputum from the lungs or coughing up blood or mucus mixed with blood, shortness of breath and chest pain.

Bronchiectasis also occurs when the air passages that allow bacteria and mucus to build up and pool in the lungs are damaged which results in frequent infections and blockages of the airways.

Although Bronchiectasis are usually permanent condition and there is no cure for it but it can be manage with treatment making the infected person to live a normal life.

when comparing the cases, what similarities are there in the cases that suggest one person committed these murders?