From the sounds of it...rarely.
Who did he interact with face-to-face other than his mother?
Has anybody been quoted in the media saying they had spoken/seen him in the past few years?
Only interaction, if true, I've read so far is his trip to buy a gun (?) just days before the assault. Hope we hear more from that salesperson as to AL's demeanor, appearance, statements, etc.
ETA: And, possible interactions during gun range outings.