If Saudi Arabia Wanted Khashoggi Dead, Why Did They Do It At Their Consulate?

Am I the only person who thinks it strange that Saudi Arabia purportedly assassinated Khashoggi in their consulate? Both North Korea and Russia assassinated citizens they did not like in foreign countries but they were not foolish enough to do it in their consulate. It is called plausible deniability. The assassinations by North Korea and Russian sent a clear message to potential enemies of the government that they will never be safe. What message does an assassination at a consulate say? If Mr. Khashoggi has done something that violated Saudi laws, why not have someone in the consulate arrest him and put him on a plane back to Saudi Arabia for a trial? In Saudi Arabia, they could legally interrogate and condemn him to death. Killing him in a consulate makes no sense.