Officer Monahan died of a gunshot wound he received as he and three other officers investigated a complaint that a disorderly house was being operated on Garden Street in Brooklyn.
As officer Monahan and three other officers were searching and questioning a man in the hallway of the house, the man opened drew a gun and fired, striking Officer Monahan twice in the abdomen. Officer Monahan was taken to Saint Catherine's Hospital where he died 10 days later from his wounds.
The suspect fled the house and engaged the other three officers in a running gun battle and escapted capture. He was was apprehended the two weeks later by detectives and charged with murder.