Forgot the name of a movie, have you seen it?

There was this semi-old horror movie about this group of scientist who found a piece of Satan's DNA in a church basement. When they start researching it calamity ensues and hobos turn into zombies and start attacking the building they're in. Only got to see part of it, but I'm a pretty big horror / zombie film junkie and would like to see the rest but I don't know the title. If this sounds familiar to someone, please let me know the title. Thanks.