The Houston PD's Chief, Troy Finner, just confirmed what we'd been told ... namely, that at least one person had been injected with something via needle -- and there well may have been more.
Chief Finner said a security guard working the event felt a prick in his neck by an unknown assailant while he was trying to restrain a citizen -- and he quickly fell unconscious. Finner says the guard was revived by use of NARCAN ... and that medical personnel did, indeed, see something on his neck that indicated he'd been stabbed with a syringe