It looks like Centerville PD is on the
MARCS-IP P25 System. I found the following Montgomery County Talk Groups in MARCS-IP.
Ohio MARCS-IP: Multi-Agency Radio Communications (P25) Trunking System, Various, Ohio - Scanner Frequencies
TG...... Alpha Tag....Description........................Tag
58160 CVPD DISP Centerville Police Dispatch Law Dispatch
58161 CVPD TAC1 Centerville Police Tac 1.....Law Tac
58166 CPD.............Centerville Police................Law Talk
Montgomery - County Montgomery: 853.600c, 853.325a, 859.4625a, 859.9625a
Closest Montgomery Towers: 2 PRESTIGE PLAZA, CARPENTER RD
Greene - Greene County: 858.8875c, 855.8375a, 856.8875a, 857.8875a
Closest Greene Towers: 3324 UPPER BELLBROOK RD, CARPENTER ROAD, 2541 US-42.
Just to be safe, I've provided the necessary MARCS-IP info for both Montgomery and Greene Counties.
FYI: The lower case c and a following the frequencies designate the (c) Control Freq and the (a) Alternate Control Freq's.