IP address of desktop PC in a domain environment

I am reviewing some logs relating to remote access to a windows server. I need to try and prove if the connection came from a specific PC, the logs however capture IP address and nothing more specific to a machine name. The suspected machine is a desktop PC in an office with a LAN cable in the back of it permanently. The machine is never physically moved or connected to other network points around the building. I am not from a networking background, so wanted some idea in this case, is the IP address of that machine likely to be the same permanently, or is the IP different every time the machine logs into the network? What windows networking tools could be used to see what IP a machine was assigned each time it connected to the network to see if its the same each time? Out of interest, under what circumstances would the IP assigned to the PC change, just to give it some context?

and presumably its irrelevant which user logs into that machine, in regards to the IP address, e.g. 2 different users logging into the domain via that device would get the same IP address?