UnitedHealthcare Shooting Suspect Seen on Video Riding Bike After Killing

Police say the suspect who killed UnitedHealthcare CEO Brian Thompson can't hide forever in NYC ... 'cause security cameras recorded a person believed to be the shooter riding away from the murder scene.

Check out the new video, obtained by ABC News, showing a person -- who cops say is the suspect -- riding down a Manhattan street just minutes after Thompson was shot to death early Wednesday outside a hotel.

It appears the rider's wearing a mask, riding down the street very quickly ... but, cops say this is the person they're looking for -- blending in with the rest of the concrete jungle.

As we told you ... Thompson was attacked just before 7 AM Wednesday -- when the suspect walked up behind him, calmly pulled out a gun and fired multiple shots at Thompson.

Thompson was rushed to a hospital where he was pronounced dead.

Photos of a person of interest -- who appears to be the suspected shooter -- have been released by cops ... giving people a look at the suspect's face for the first time. The suspect appears to be wearing different clothes -- it's unclear when the images were captured.

Cops are actively investigating the shooting ... raiding the New York International AYH-Hostel where the killer allegedly stayed before shooting Thompson.

We spoke to Matheus Taranto -- a man visiting from Brazil and staying at the same hostel -- who says he couldn't access certain parts of his floor because cops were there. Taranto said he did not recognize the man in the suspect photos.