The first person I suspected to be the Ripper was a policeman, as it was so strange how many of them were out on the streets patrolling like there was no tomorrow, but the Ripper still managed to kill. If the Ripper was a policeman or had any connection to the Police, then they most likely left the job or had been dismissed before the killings began. Someone on the boards a few years back had also suggested that Jack may have been an employee of the Transport or Railway Police and made his escape via railway lines/tracks. I guess this is still up for discussion/debate.
The autumn or terror could be explained by more LE out on the beat and if JtR was LE then he could have been one of them and in the perfect position to carry out a string of attacks over a short period of time.
So what changed after the murder of Mary Kelly? He seemed to have 'stopped' or at least slowed down.
Bona fide canonical and then some.