Who done it sp_blitz
First, sp_BlitzLock only helps you analyze deadlocks, not blocking. 

Second, it won't run on 2008R2 -- it's 2012+ only. The deadlock XML definitions are sufficiently different to make supporting both unwieldy. 

Third, it already includes the timestamp of the deadlock event, along with other identifying information. I don't think spid would be helpful.