When I was a kid [in N.Z.] the bike cops rode Triumph Saints, you could even pick `em de-mobbed, still with the single seat & extra electric fittings,: TR6P engine I.D. prefix, & E 3134 cams [actually, some may have been prematurely 'liberated' from.. ah - servitude, by.. er,hoodlums - & they were pretty quick for the day, -then the coppers ran a bunch of late production BSA T/bolts, [Govt must`ve got a job lot cheap] . Never saw Nortons though..
By the time I was personally concerned about cop bike performance [mid `70s] - the poor bloody rozzers had overloaded, unwieldy parade junk such as Suzuki GT 550 [! ]triples & the inevitable Honda 750/4s, not much cop [`scuse the pun] as pursuit machines, real dangerous to the riders in fact, with all that added top hamper on already vague roadholding machines from standard...