BEDFORD-STUYVESANT, Brooklyn (PIX11) – Police are on the hunt for a suspect in the stabbing death of 32-year-old political activist Ryan Carson, who was killed around 3:45 a.m. on Monday in Bed-Stuy.

According to police, Carson and his girlfriend were sitting on a bench at the Lafayette Avenue and Malcolm X Boulevard bus stop when a man in a Champion hooded sweatshirt walked past them.

As Carson and his girlfriend got up to walk home, the man began kicking mopeds and scooters on the sidewalk, video of the attack obtained by PIX11 shows.

Police said the man then turned to Carson and asked what he was looking at. Carson reportedly placed himself between the man and his girlfriend to protect her.

Investigators say the man then pulled out a knife and wielded it at Carson, who tripped over a bench as he backed up. Police say the man stabbed Carson three times, including a fatal stab to his heart. The man then kicked Carson, threatened to stab Carson’s girlfriend, spit in her face, and ran off, the video shows.

Police say an unidentified woman then arrived at the scene, apologized to the victim and muttering the name “Brian.”

Investigators believe that the woman is the suspect’s girlfriend.

Submit tips to police by calling Crime Stoppers at 1-800-577-TIPS (8477), visiting, downloading the NYPD Crime Stoppers mobile app, or texting 274637 (CRIMES) then entering TIP577. Spanish-speaking callers are asked to dial 1-888-57-PISTA (74782).