Disillusioned with housing prices and schools in the District of Columbia, Robert Mott and his wife decided about eight years ago to move to Prince George's County. After house-hunting for months in Washington and Arlington, Mott decided to buy a $28,000 home in Hillcrest Heights. A few years later he moved into a $70,000 home in Camp Springs.

Recent studies indicate that the Motts were among the first in a still growing exodus of black middle-class families who are leaving Washington to find their dream homes in Prince George's County.

Their influx is changing the racial and economic profile of Prince George's, where county projections indicate that the black population is growing and income levels are rising.

A Maryland-National Capital Park and Planning Commission study concludes that "the racial mix of the population has shifted from about 15 percent nonwhite in 1970 to 30 percent nonwhite in 1977 . . . The black immigrants to the county as shown by the Census Bureau data are predominantly the middle-income, more affluent blacks in the metropolitan area."

The county Department of Program Planning and Economic Development says that the white population has dropped from 571,082 in 1970 to 435,290 in 1979. During the same period, the black population has increased from 92,118 to 231,290.

County officials and civic leaders say much of the movement has been into southwestern Prince George's County just across the line from Southeast Washington. There, in communities like Tantallon, Tor Bryan, Temple Hills and Hillcrest Heights, black middle-class families are moving into new homes valued at $40,000 to $150,000.

While many of the older neighborhoods are integrated, many of the newer developments like Ashford Place and Prophecy are not.

Several southwest county residents said they believe real estate salespersons may be steering black home seekers to all-black developments. Though most families interviewed conceded that some families may prefer to live in a predominantly black neighborhood, they agreed that a great many do not.

"It seems awfully strange to me that so many of these new developments would be all black," said one Temple Hills area civic leader. "Newcomers are the easiest ones to steer since they don't know the area well. The realtors have almost total control over what they see and what they don't see."

The general area where the influx is most pronounced is one of the last, partly undeveloped sections of the county that borders the District. During the last 10 years, new commercial and residential structures have begun to spring up in the area, bounded on the east by Maryland Rte. 5 and on the west by Southeast Washington and the Potomac River.

Interviews with some of thenew residents indicate that many, like the Motts, moved to southwestern Prince George's County because they feel that the prices for new homes are more reasonable and because of their proximity to the District.

"I moved to Prince George's County because you get more value for the money you pay," said Mott, noting also that he had to pay less for his car tags and his car insurance.

He adds, "There were black families in Prince George's County, and my little sister could go to what was perceived to be a better school system in Prince George's County."

"That house (purchased for $70,000 in Camp Springs) would have cost us at least $100,000 if we had bought it in the District or one of the other counties," said Mott, who has a combined income with his wife of $45,000 to $50,000.

Though Mott remains convinced that property values are more reasonable than those in the District or Montgomery and Fairfax counties, his opinion of the schools has changed.

"Some of the problems predominant in the District are beginning to pop up out here," he says. "You now find kids milling around a lot of the Prince George's schools.The discipline I used to see is almost gone."

Mott said many of his neighbors have begun sending their children to parochial or private schools.

"Most people just don't think the public schools system is of very high quality," he added.

James Taylor decided to try private schools for his daughter. Taylor took her out of Suitland Senior High School two years ago so she could complete her last two years of secondary school at Camp Springs Christian School.

"I didn't think my daughter had any business going to a school with nearly 2,000 students where she couldn't get her individual needs taken care of. I had also heard a lot of negative stuff about Suitland," said Taylor. "Looking back, I think sending her to a private school paid off quite well."

Taylor says he will probably send his son, now in the ninth grade, to a private school.

Otis Ducker, a black candidate for the school board last year from southwestern Prince George's, said other parents are doing the same thing for largely the same reason.

"The Prince George's school system has a long way to go. A lot of people are looking to private schools to equip their kids to compete because they don't have very much confidence in the public schools," he said.

However, Allan Chotiner, deputy superintendent of the Prince George's County Public Schools says, "We're not aware of any movement from public schools to private schools. There's no indication that people from that part of the county are losing confidence in our schools."

While there is some disagreement over whether new residents still move to the county in part because they think the schools are better, there seems to be a general consensus among black and white residents that integration has come about fairly smoothly.

"When we first moved in, we would catch people peeping out of their windows, but now everyone seems comfortable with us," says Robert Mott who lives in a predominantly white neighborhood.

Robert Jones, a resident of Temple Hills and a member of the county and state Democratic Central committees, says that neither he nor many of his neighbors have decided to leave because the neighborhood is now racially mixed.

"As far as I know," Jones said, "there has been only one resident who has left because of integration.

"If anybody's causing problems, I'd say it was the realtors. They are probably doing a lot of steering. Look at Hillcrest Heights. Ten years ago, it was almost all white. Now it's almost all black. Even though people may sometimes like to live with others of the same race, there are many who probably want to live in integrated neighborhoods but are steered."

Marvin Gay, a 10-year resident of the southern Maryland area and a former commissioner on the Washington Suburban Sanitary Commission, says that another concern for new residents is how to make the psychological adjustment to Prince George's County.

"A lot of the new people still have to overcome the D.C. syndrome," Gay said. "They think they still live in D.C.

"I still run into people who are still trying to find out what Marion Barry and the City Council are doing, instead of keeping an eye on Larry Hogan and the County Council."

State Sen. Tommy Broadwater, estimates that there are 20,000 to 30,000 new voters who moved from Washington who have not registered in Prince George's County.

"I don't know what is going on," Broadwater said, "but evidently some people still think they owe their allegiance to D.C.

"I guarantee you that if that 30 to 35 percent black voter population would register, you'd see some new faces in the state legislature and some new faces in the county courthouse."

Broadwater added, "Some people in this county believe that blacks are trying to take over, but that's not true. Blacks only want their fair share of the representation."

He said that many whites had jumped to conclusions about "blacks trying to take over" because of the increasing black population without finding out if blacks are registering to vote.

For the time being, Broadwater says that the new residents will have to become attuned to what is going on in their own jurisdiction.

"I only hope the people moving down into that area don't forget from whence they came," he said, alluding to fears that discrimination might resurface. "Prince George's County is become a fairer, more integrated county but unless people get involved in their communities on a civic level, the county government will not pay them any mind."