MILWAUKEE (CBS 58) -- A 21-year-old Milwaukee man is charged with battery to an elderly person and battery to a law enforcement officer after a 63-year-old man was knocked unconscious outside Fiserv Forum, according to a criminal complaint.

Alandis Tribblett also faces charges of disorderly conduct and resisting an officer.

Police responded to the area near Fiserv Forum on Juneau Ave. at around 10:14 p.m. on Sunday, Sept. 13 and found the 63-year-old man unresponsive under a shuttle bus with blood around his mouth, the complaint states.

Officers found Tribblett standing near an open manhole in the street, talking about underground tunnels and child trafficking, according to the complaint. Witnesses reportedly told police Tribblett had been climbing in and out of a manhole and banging on parked shuttle vans for about 30 minutes.

One witness is cited as telling police that she saw Tribblett shove the older man to the ground, while another told police he saw Tribblett punch the man, causing him to hit his head on the van and lose consciousness.

The older man later told police he'd walked over to check on a van driver and remembered Tribblett asking if there were kids in the vans. The next thing he recalled was waking up underneath the van, according to the complaint. After his arrest, Tribblett bit an officer's gloved hand at the hospital, leaving a bruise, according to the complaint.

Tribblett has not been convicted. The charges are allegations. His next appearance in court is scheduled for Wednesday, Nov. 4.