A jury rejected Robert Goulding's argument of an assisted suicide and convicted him of first-degree murder after about 30 minutes of deliberation Thursday.

The 52-year-old Rapid City man was charged in the shooting death of 56-year-old Allen Kissner near Sheridan Lake in November 2008.  Jurors saw a taped police interview in which Goulding confessed to pulling the trigger and said Kissner "practically begged me to do it."  Defense attorney Tim Rensch called it an "act of mercy." 

Prosecutor Lara Roetzel told the jurors in closing arguments that it was murder and their decision wouldn't be hard or tricky.