Detective Rockford was jogging near the beach ar 4:30 am.
He hears a sound near the shack "No Michael, Please Do not shoot me".
Next instance he heard a sound of gunfire. Rockford rushes to shack where he finds women lying dead and a gun in close proximity of three "Doctore Lawyer and a Teacher".

Rockford immediately knew that the Lawyer has committed the crime. How ?

Lawyer was the only man there (Michael is name of a man)