I used to hear Tishomingo PD several years ago in 155.490 their call sign was KRZ-328 Can't hear them anymore. The only thing listed in the RR database is Johnston County .
They may still be on 155.490 then. Another possibility is they have moved to the OKWIN system since there is a site there.I can hear Johnston County but No PD on the County freq, they might still be on 155-490 with no license or using the county license. I don't monitor 155.490 as birdies from the computer locks up that freq.