Who is the mystery man on the roof? That's what Twitter and Boston bombing conspiracy theorists want to know in the wake of yesterday's explosions.
A photo credited to Suffolk University junior Dan Lampariello shows the instant of two Boston Marathon bombings that occurred near the finish line Monday.
The photo, and with it Mystery Man on Roof, went viral.
Lampariello told ABC News Monday "I was about 200 feet from the finish line ... right in front of the Mandarin Hotel. My aunt was running in the marathon."
"We were out there to cheer her on. We thought maybe it was fireworks at first, but when we saw the second explosion we knew something was wrong."
As if the Internet weren't going berzerk enough over blasts that killed at least three people and injured more than 170 more, many gravely, there's this.
Police say they have no suspects yet, and no individual or group has claimed responsibility for the attack, which only feeds interest in the MMOR.
A lack of real leads - the alleged suspect in custody is not believed to have been involved, and his name has not been released - breeds speculation.
Here's what is happening on the investigative front:
Last night, agencies raided a unit in a high-rise apartment on Ocean Drive in the seaside Boston suburb of Revere, according to local police officials.
Several bags, including what appeared to be a large duffel bag, were removed from the scene. Details are scarce, but the search was related to the case.
Boston police also issued a BOLO for a yellow Penske rental van that apparently attempted to access the race course area shortly before the blast.
They are also looking for a "black man wearing a black hoodie and a black backpack" who was turned away from a secure area shortly before the bombings.
As for Mystery Man on Roof?
He could be the perpetrator of this senseless act of terrorism ... or just a guy looking for an awesome vantage point for one of the city's coolest events.
Probably the latter ... but don't let logic stop you, Twitter.