'Today' Intruder Suspect Is a Sandy Hook Conspiracy Theorist, Memorial Vandal

The "Today" show intruder suspect is a conspiracy theorist with a lengthy rap sheet ... which includes doing hard time for vandalizing multiple Sandy Hook Elementary School memorials.

Andrew Truelove -- who's been charged with several crimes connected to Thursday's scary incident involving Craig Melvin and Al Roker -- spent years behind bars after he copped to stealing signs memorializing victims of the deadly school shooting.

The transient suspect is a hardcore Sandy Hook conspiracy nut ... and the Los Angeles Times reported that was his motivation when, in 2014, he traveled to playgrounds in New Jersey and Connecticut to steal the memorial signs.

TMZ broke the story ... Truelove slipped past security at 30 Rock Thursday morning and was asking for Al. When he couldn't find the famous weatherman, he turned his attention to Craig, confronting him in a restricted area and allegedly lunging at him while yelling the n-word.

Police say a witness -- who appears to be Craig -- told them Truelove made a statement about always wanting to use the racial slur in the face of a Black celebrity.

Law enforcement tells TMZ ... Truelove can't go near the two men at NBC or their homes -- which for the moment is moot because he's still behind bars on $20,000 bail. He's currently being held at Rikers Island as he faces a bunch of hate crime charges.

Craig told us he's fine Friday and is chalking it up to "a lot of wacky out there."