Forget about roots, what if i have 20 'user' account on the box.
For example:

gfadm pts/0 Feb 12 08:38 (apdv1-26)
gfadm pts/7 Feb 12 15:32 (apdv1-26)
root pts/1 Feb 12 14:10 (apdv1-26)
gfadm pts/4 Feb 12 11:15 (gfbtap1)
gfadm pts/5 Feb 12 14:44 (gfbtap4)
root pts/16 Jan 25 12:38 (apdv1-26)
gfadm pts/12 Feb 8 08:44 (apdv1-26)

and i am interested in the last 'gfadm' on pts/12

how can i find our where did he come from and what was he logged on as?

Thanks!!