To Juanita Robinson, her son-in-law Vincent J. Dortch was a "very nice person" who treated her daughter, Stephanie, well.

She was shocked to learn yesterday that Philadelphia police say the Delaware man killed three people and himself at the offices of a marketing company at the Navy Yard business center. Police say he believed he was the victim of business fraud.

"That just doesn't sit right with me, because I don't know him to be that kind of person," Robinson, 78, said yesterday in her apartment in Newark, Del. She was not aware that Dortch had any guns.

"He was a very nice person. He didn't strike me as someone who would be violent. That's the size of it."

Robinson said she lived with Vincent and Stephanie Dortch for several years in a five-bedroom, two-bath, split-level house in Newark until June, when it sold for $270,000. Robinson said she and Stephanie Dortch owned the home. The "tall, very handsome" Vincent moved in "four or five years ago" when the couple married.

Robinson lived in a mother-in-law suite in the home's basement and said she tried not to meddle in the couple's affairs. She thought Vincent Dortch, 44, who was originally from New York, worked as a truck driver and had been looking for a job recently. She thought he had found a new job at a railroad.

She never heard the couple arguing and was not aware of any financial problems. Vincent Dortch had a Lexus, she said.

Kenneth James, the listing real estate agent for the Dortches' house, described it as "immaculate" and said it sold within a week.

Karen and Allen Babcock, who lived across the street from the Dortches, said the couple did a lot of home improvements in preparation for selling the house, including installing new carpets and a garage door.

Another neighbor, Jynx Stevenson, 40, said that 21/2 years ago, Dortch, unasked, mowed her lawn while she and her husband, Jeff, and their newborn daughter were away on vacation.

Both the Babcocks and the Stevensons described the Dortches as a quiet, pleasant couple. The Babcocks said the Dortches dressed well and had nice cars.

"I feel sorry for the whole family," said Jynx Stevenson.

After the house was sold, Robinson moved into an apartment and plans to move soon to a facility for senior citizens. The Dortches were living in a different Newark apartment as they thought about buying another home, according to James, the real estate agent. James said they told him they'd like to live in an upscale development like the one that Robert E. Norris - one of the men police say Dortch killed - lived in.

Allana Ludwig, a neighbor at the apartment complex, said that she had met Dortch only once, and that he kept to himself but seemed like a nice person.

"We didn't really see him around too much. It's a pretty quiet area," Ludwig said. "It's just scary to think somebody like that could live so close."

Federal records show a 2003 tax lien against Dortch for more than $9,000.

Contact staff writer Mari A. Schaefer at 610-892-9149 or mschaefer@phillynews.com.

Free-lance journalist writer Brian Citino contributed to this article.