In the final days before a gun battle with sheriff's deputies yesterday left him dead, Richard E. Hummer felt the world was collapsing around him. Unemployed, sick and deeply in debt, he fought to stave off eviction from his College Park home.

"I need help today or I will be killed," the 59-year-old electrical engineer wrote in an e-mail appeal launched into cyberspace Wednesday. "I need help now to stop this eviction . . . time to get these messes fixed up."

When Prince George's County sheriff's deputies with eviction papers knocked at his brick house on Nantucket Road yesterday afternoon, Hummer began shooting as he opened the door, authorities said. One deputy fell with a graze wound to the head, and the ensuing exchange of gunfire left Hummer dead.

In the aftermath, there emerged--from a review of Hummer's e-mail and interviews with neighbors--a portrait of a man whose life became increasingly troubled in recent years, ending in a sharp tailspin with his car repossessed, his electricity turned off and his eviction pending. He became reclusive, painted his windows black, always wore dark glasses and traveled by bicycle, neighbors said.

On Wednesday, Hummer sent out a lengthy, rambling e-mail recounting 19 of the problems that had beset him, beginning with a 1995 bicycle accident that he said resulted in the loss of his job. Filling more than two printed pages, the message complained that his computer crashed too often, that bureaucratic red tape had caused his problems with mortgage and loan companies and that he had been mistreated by various lawyers and insurance companies. He said that if the threatened eviction were carried out, it would "destroy [his] diet-exercise program."

Several Washington Post editors and reporters were among the recipients of the e-mail, which was so rambling in nature that it undermined the severity of his despair.

His troubles had come to the attention of authorities, and six deputies were dispatched rather than the normal team of two when it came time to serve the eviction papers yesterday.

After Hummer responded to their knock by opening fire, deputies dragged their wounded colleague to safety and engaged in a gun battle that lasted about eight minutes, police said.

The final volley occurred when Hummer walked out of the side of his house and took aim with a shotgun at the deputies, who fatally shot him as he stood in the grass, police said.

Ray Noll, 71, a retired milkman who lives across the street, said he was reading the newspaper by his picture window when the gunfire broke out. He said he heard what sounded like several bursts, totaling about 20 shots.

"When I first heard the shots, the dog and I both jumped at the same time," Noll said. "I looked out the window. I could see the police returning fire to his house."

He then saw the deputies scatter, apparently when Hummer fired, and duck behind patrol cars.

"After it quieted down pretty much, there was a police officer on a bullhorn saying, 'No one has gotten hurt yet, Richard. Please come out.' He repeated that over and over."

Large clouds of black smoke spilled out of the windows shortly after the shooting began. Capt. Mark Brady, a Prince George's Fire Department spokesman, said Hummer set a fire "as a diversionary attempt so he could engage and startle" the deputies. The fire burned for about 10 minutes.

Police evacuated most of the homes in the 5000 block of Nantucket Road, in the Hollywood neighborhood of North College Park, just south of the Capital Beltway. Some residents were ferried out of their homes in armored vehicles, while others cowered in their basements for hours.

Hummer was pronounced dead at the scene. The injured deputy, whom police declined to identify, was released after treatment at Prince George's Hospital Center in Cheverly.

Authorities declined to say who had sought Hummer's eviction, although officials confirmed that a man representing a private firm that had sought the action had accompanied sheriff's deputies to serve the papers. Sources close to the investigation said Hummer had defaulted on mortgage payments after he repeatedly tried to refinance a variety of loans.

Neighbors described Hummer as a tall, thin and gray-haired recluse who had lived on Nantucket Road for most of his life. They said he rarely emerged from his brick house, which is covered with vines and surrounded by thick bushes and trees. One resident said he had blacked out his windows, even though they were scarcely visible from the street.

Paul Voss, 42, who has lived on Nantucket Road for 12 years, said Hummer became even more of a loner after his wife died about 10 years ago. He said Hummer rarely spoke and wore dark sunglasses as he rode his bike up and down the street throughout the day.

"Since his wife died in the car crash, he just kept to himself," Voss said. "He never said anything. We never heard anything from him. That's what got me."

Cesar Toledo, who lives next door, said Hummer graduated from the nearby University of Maryland at College Park, where he studied computer science. Toledo said the only time he saw visitors at Hummer's home was when people would drop off computers for him to repair.

Hummer had been unemployed for several years, Toledo said, save for a couple of computer-related jobs that lasted only a few months.

"He's a really intelligent guy," Toledo said. "He can really fix computers. I don't know why he wasn't able to find a job, because he had good qualifications."

Another neighbor, Connie Brain, said that her father-in-law had worked with Hummer on electrical engineering projects in the 1980s and that he had described Hummer as "a real genius."

Prince George's court records show that since 1993, Hummer had received 40 citations for minor motor vehicle infractions, such as failure to cover or remove an untagged vehicle from his property. In addition, court records show Hummer owed $1,010 to the City of College Park and $663.70 to his dentist, Gary R. Alexander. The dentist did not return a reporter's call, but a woman who identified herself as Alexander's office manager said, "We all remember him. He just seemed like an average guy."

In his e-mail, Hummer gave a rambling account of prolonged financial problems and his inability to find lasting employment. He also described a long history of health woes, including diabetes.

"Well, they are going to through [sic] me out of my house tomorrow," he wrote. "I'm not helpless and will work anywhere that's possible. But I haven't been able to solve the above problems and stay alive in the time allotted."

Staff writers Michael E. Ruane and Eugene L. Meyer, staff researcher Bobbye Pratt and special correspondent Dave J. Iannone contributed to this report.

CAPTION: An officer in heavy gear arrives during the standoff after a man being served with eviction papers opened fire on Prince George's sheriff's deputies.