Cell site analysis uses the records that mobile networks keep of which masts a handset connected to, and when. It can place a phone in a broad area consistent with a mast's coverage, and it can rule out areas the phone cannot have been in. It cannot pinpoint a phone to a specific address, and it should not be presented as if it can.
What the records actually show
Call data records list the mast and sector a phone used at the time of each call, text or data session. Coverage from a mast is not a neat circle. It is a wedge shaped area that changes with terrain, buildings, load on the network and the direction the antenna is pointing. Proper analysis requires the antenna configuration for the relevant date, which the network will disclose on production.
Where it goes wrong in court
- Presenting mast coverage as a point rather than an area.
- Ignoring changes to the network between the incident date and the analysis date.
- Relying on the nearest mast assumption, when the phone often uses a mast that is not the closest.
- Confusing the location of the phone with the location of the person, when devices are shared.
Getting the evidence right
A defensible cell site report combines the network's own records for the relevant dates, a site visit or drive test where the area is contested, and clear language about what the evidence can and cannot support. It is a specialist discipline; general mobile forensics experience alone is not enough.