Final hours of former Pentagon official puzzle his neighbors

New Castle, Delaware -- Neighbors of the former Pentagon official whose body turned up New Year's Eve morning in a garbage truck in Wilmington, Delaware, expressed bafflement Thursday over what authorities have pieced together about the mysterious and bizarre final hours of John P. Wheeler III.

"I think, 'Gosh! What's he doing? I've never seen him like that before,' " neighbor Phoebe Dill told CNN after viewing video from a security camera. It showed the 66-year-old man, who once headed the Vietnam Veterans Memorial Fund, stumbling around a parking garage shortly before 7 p.m. December 29. He's holding a shoe in his left hand and is wearing a dark suit, without a tie.

Occasionally, he touches a wall as if to stabilize himself.

"Obviously, something was wrong."

Phoebe Dill's husband, Robert, said he, too, was flummoxed. "I've been running it around in my head; I can't even put the pieces together. I have absolutely no idea."

The police have not been able to determine how Wheeler got from an office and apartment building in Wilmington to a Dumpster in Newark, Delaware, about a dozen miles away.

Authorities believe a garbage truck picked up his body around 4:30 a.m. on December 31 from one of 10 commercial Dumpsters in Newark before driving to the landfill.

Workers there discovered his body jutting out of a garbage truck and called police.

Authorities have declined to describe the condition of Wheeler's body but have said his death was a homicide.

Wheeler's vehicle turned up near Wilmington's Amtrak station in a different parking garage.

Police have pieced together some of what happened during the days before his death through first-hand accounts and two surveillance videos -- one of which has not been made public -- that paint a picture of a disheveled and confused man wandering between New Castle and Wilmington.

Lt. Mark Farrall of the police department in Newark said Wheeler walked into a pharmacy near his home in New Castle at 6 p.m. December 29, two days before his body was found, asking for a ride to Wilmington.

Pharmacist Murali Gouro, who had filled prescriptions for Wheeler in the past, said he offered to call him a taxi, but Wheeler declined the offer, Farrall said.

Iman Goldsborough, an attendant at the parking lot where the security video that has been released was shot, said the man she now knows as Wheeler wandered into the garage some 40 minutes later carrying a shoe and looking disheveled.

"I'm not drunk, I'm not drunk," he said, according to Goldsborough.

Though temperatures were in the 30s, he wasn't wearing an overcoat. He couldn't remember where he had parked his car and said his briefcase had been stolen, she recalled.

As late as 8:30 p.m. the next day, December 30, security cameras recorded Wheeler in a separate office building in downtown Wilmington, a police statement says.

"We know that he was contacted by several individuals within that building between the hours of 2:30 p.m. and 3:30 p.m. on the 30th," and that they offered him help, Farrall said. But Wheeler, who appeared confused, declined the offers, according to the police statement said.

Farrall said Wheeler was wearing clothes similar to those he had worn the day before at the parking garage, except this time he was also wearing a dark sweatshirt.

Police said the second video was shot on the ninth and 11th floors of the Nemours office building in Wilmington.

Investigators are searching for Wheeler's briefcase as well as for the crime scene. "If we can find the location where this happened -- that will lead us hopefully to the killer," said Farrall.

Newark police, the lead investigators in the case, are consulting with the FBI, Farrall said.

Farrall said a dispute between Wheeler and a neighbor is being looked at as "one facet of the investigation."

Wheeler's attorney, Bayard Marin, told CNN that his client had been involved in a lengthy legal fight with a couple building a home across the street from his home in a historic district of New Castle, about six miles south of Wilmington. Wheeler opposed the new construction.

The dispute may have become contentious, but "I can't recall a confrontation," Marin said. "Everything seemed to be kept within normal bounds."

Wheeler had worked as a part-time consultant for the MITRE Corporation, a not-for-profit organization that provides systems engineering, research and development and information technology support to the federal government.

He had been been working on promoting discussions about cyberdefense among governments, industry and academia, according to a company statement.

The West Point graduate was an advocate for Vietnam veterans. He worked in the administrations of Presidents Ronald Reagan, George H.W. Bush and George W. Bush. He served as a special assistant to the secretary of the Air Force from 2005 to 2008.

While in the Army, he served as a staff officer in Vietnam and later helped push for acceptance of the Vietnam Memorial in Washington.

CNN's Sheila Steffen, Ross Levitt, Susan Candiotti and Sarah Hoye contributed to this report.