Find out who ran a query using transaction log backups We have a SQL Server 2012 Enterprise database running in Full Recovery Model with transaction log backups running every minute. A query was run last night which means we need to recover data from a certain point in time - so we restore transaction logs to that point in time, recover the data we need, all good.

What we want to know, is there a way that we can tell what login ran a query using the transaction log backups?
Converting my comment as answer :

You have to use undocumented fn_dblog Begin Time, SUSER_SNAME([Transaction SID]) or fn_dump_dblog -- when reading from T-log backups. Be careful and try it on a NON PROD system as every time fn_dump_dblog is called, it creates a new hidden SQLOS scheduler and up to three threads, which will not go away (and will not be reused) until a server restart.

Also, its not that straight forward to be able to read T-log and come on a conclusion - If you have not done it or are new to it. You are better off trying a 3rd party tool (like Apex SQL Log) if it is that critical for you to find out who did the mess.