GAINESVILLE, FLA., AUG. 31 -- An 18-year-old University of Florida freshman charged with beating his grandmother was held today on $1 million bond, and police investigating the deaths of five university students sealed his apartment.

Police said Edward Lewis Humphrey, who earlier this summer reportedly lived at the apartment complex where two of the bodies were found this week, is among the potential suspects in the slayings.

"We continue to have a pool of suspects," said Alachua County sheriff's Lt. Spencer Mann. "To say that we have a prime suspect or prime two suspects or three suspects is very premature."

Humphrey was arrested Thursday at his grandmother's house in Indialantic, about 180 miles to the southeast, and charged with aggravated battery on a person over age 65, authorities said. His grandmother was treated at a hospital for a fractured jaw and eye injuries after he allegedly beat her.

"There's a lot of good information that we have received that seems to bear some credence that he may be a possible suspect," said police Lt. Sadie Darnell.

Darnell also named Warren Virgil Tinch, an Ohio fugitive wanted in a mutilation murder, and a man named Stephen Bates held in Polk County in a burglary and assault case, as potential suspects.

Police also were looking for a man wearing camouflage pants who fled when a state trooper tried to question him here early today.

At Humphrey's jailhouse court hearing, Brevard County Judge Kerry Evander found probable cause to hold the student for trial in late October. Humphrey asked the judge if he could say something.

Evander told him to ask his attorney, public defender J.R. Russo, but the stocky youth blurted in a clear, emphatic voice: "Innocent 'til proven guilty."

Brevard Circuit Judge Dean Moxley increased Humphrey's bond from $10,250 to $1 million after two Florida Department of Law Enforcement agents spent about 12 hours at the jail where he was being held.

The victims -- students at either the University of Florida or Santa Fe Community College in Gainesville -- were stabbed to death in off-campus apartments in three attacks discovered since Sunday. Police said three of the four women were mutilated.

A Florida Department of Law Enforcement plane followed Humphrey as he drove Wednesday from Gainesville to his grandmother's house. Neighbors said he had experienced emotional problems since suffering a severe head injury in a traffic accident more than a year ago.

Funeral services were held today for four slaying victims in their home towns: Christina Powell, 17, of Jacksonville; Christa Hoyt, 18, of Newberry; Tracy Paules and Manuel Taboada, both 23 and of suburban Miami. The fifth victim, Sonja Larsen, 17, of Pompano Beach, was buried Thursday.