The alleged stalker posted a selfie outside the singer's home on April 30 but by the time police arrived he was gone.
He also sent several menacing messages to and about Rihanna.
TMZ reported Sunday the user account from which the tweets were sent is listed under the names of Alex Mercer and Ralph Alexander and police are now tracking the suspect electronically.
Rihanna looks downcast as she heads to the gym as police search for stalker who posted threatening gun tweets and a selfie outside singer's house!
Rihanna looked down in the dumps as she tried to maintain her regular routine after an alleged stalker sent her gun threats via social media.
The R&B star, 27, was seen heading for the gym in the SoHo neighborhood of New York on Monday and appeared subdued, dressed down in workout gear and wearing a large pair of sunglasses.
It follows the news that law enforcement continues to search for the man who posted the threatening tweets, including one of a gun and bullets.
The alleged stalker posted a selfie outside the singer's home on April 30 but by the time police arrived he was gone.
He also sent several menacing messages to and about Rihanna.
TMZ reported Sunday the user account from which the tweets were sent is listed under the names of Alex Mercer and Ralph Alexander and police are now tracking the suspect electronically.
The alleged stalker posted a selfie outside the singer's home on April 30 but by the time police arrived he was gone.
He also sent several menacing messages to and about Rihanna.
TMZ reported Sunday the user account from which the tweets were sent is listed under the names of Alex Mercer and Ralph Alexander and police are now tracking the suspect electronically.