When postal clerk Guy Washington got home from eight wearying hours sorting and distributing mail, there was nothing he liked better than sitting down and switching on his most prized possession -- a $1,000 stereo system.

But all that came to an end on April 9. On that day he walked into his Southeast Washington apartment after work and discovered that the stereo, for which he'd saved for months, was gone.

His apartment had been burglarized.

"I couldn't believe it," he said as he sat in his sparsely furnished apartment recently. "I don't have much. I'm just making it by the skin of my teeth."

Washington is just one of thousands of District residents who have suffered as the result of a dramatic surge in the number of burglaries, which are being committed largely by heroin addicts and juveniles.

From the spacious and elegant homes in Georgetown and Upper Northwest to the run down housing projects in Far Southeast, these "criminals of opportunity" -- some as young as 9 years old -- are preying on the rich and poor with increasing frequency, police say.

Burglaries "are up all over," said Deputy Police Chief Carl V. Profater of the 5th District. "I'm sure that economics has a lot to do with it."

Burglaries increased 8 percent in the city last year, the first increase since 1974. And for the first six months of this year they have gone up 17 percent, making burglary one of fastest growing major crimes in the District.

Each of the seven districts in the city shows an increase. For the first six months of this year, burglaries are up 44 percent in the 2nd District, which includes Georgetown and Cleveland Park; 24 percent in the housing projects, apartments, and homes of the 7th District in Far Southeast; 20 percent in the 1st District, which includes renovated areas of Shaw and Capitol Hill; 11 percent in the 5th District in Northeast; 5 percent in the 4th District, which includes Takoma Park and Shepherd Park; 8 percent in the 3rd District, which includes the 14th Street drug corridor, and 5 percent in the 6th District in Far Northeast.

In the surrounding suburbs, latest figures show burglaries up 14 percent in Arlington; 17 percent in Alexandria; 1 percent in Fairfax County; 5.5 percent in Prince George's County, and 8 percent in Montgomery County.

Nationally, the first quarter of the year produced an 8 percent increase, the first rise for that period since 1974.

Police blame unemployment, inflation and increased drug use as reasons for the rise in burglaries.

Most burglars are unemployed, police say. According to recent crime statistics, the majority are black males in the 13-17 and 25-29 age brackets.

The majority are also repeaters, police said. Their favorite items are stereo units, television sets, radios, cash and jewelry. The stolen items are almost never recovered.

"You can commit a burglary and sell your property within one hour," said a burglary squad investigator. "There is always someone willing to buy it."

"There is no question in my mind that a substantial number of burglars are narcotic users satisfying their habit," said Deputy Chief William R. Dixon of the 3rd District.

"It's not unusual to find a junkie with a $100- to $150-a-day habit," said 7th District Deputy Police Chief James Kelly. "He has to have that money . . . . Where is he going to get it. He can't work and get that much, so he's got to rob or steal."

Last October police arrested a 26-year-old heroin addict who, they said, had committed more than 100 burglaries within 100 days. Ernest Reed, they said, would kick in the doors of renovated homes in the Capitol Hill and Georgetown areas. He would then catch a cab to an area where he would barter the goods for money to buy drugs.

Juveniles are heavily involved in burglaries. According to the latest figures, 967 youths between the ages of 13 and 17 were arrested and charged with burglary from October 1977 to September 1978.

Recently, police arrested seven juveniles in connection with more than two dozen burglaries in the Stanton Hill apartment complex where burglary victim Guy Washington lives. Several of the juveniles were 9 years old.

"They (juveniles) do it for the money," said a detective. "An older guy -- might be his brother or a friend -- offers these kids $5 to $10 to go through the window. That's a lot of money to these kids . . . and they want to be with the fellows . . . so they do what the fellows do."

The burglary of Washington's apartment in April is similar to the hundreds that occur in the city each month.

The apartment was broken into during the day, the most common time for burglars. The intruders broke a kitchen window to gain entry.

Besides stealing the stereo unit, the burglars took a 10-speed bicycle, two cameras, two portable black-and-white television sets, four pairs of shoes, clothing, including two leather coats, and $60 in cash from a kitchen cabinet.

When police arrived, they discovered footprints leading from Washington's apartment to an adjoining building.

Washington said the police told him they followed the footprints but found nothing. But after the police left, Washington said, he and a friend followed the footprints to the door of an apartment in the next building.

"We followed the footprints right to the little boy's door," Washington said, "and after we made a little fuss then it all came out that, yeah, the little boy upstairs and a couple of other little boys had broken into the apartment."

Washington said he recalled the police back and they returned to the complex that night to talk with the youth.

"The little boy that broke into the apartment, he admitted breaking in," Washington said. "He even told who had my stereo equipment. They arrested the little boy that night."

Washington, who grew up in Southeast Washington, said the youth told how he broke into the apartment with the help of some older men. "It was like one person would break in. He'd go tell a buddy. His buddy would come in. He'll go tell another buddy. Through the course of it all, about eight or nine people came through," Washington said.

Police said the youth is among seven juveniles and an adult arrested in connection with at least two dozen burglaries in the apartment complex.

The same day Washington's apartment was broken into, burglars hit four others there as well.

Polly McKinney, who shares an apartment with Jesse Fitzgerald, was another of the victims.

The intruders gained entry in that case by breaking the kitchen window of their second-floor apartment.

They took a tape recorder, a stereo unit, a briefcase, a slide projector, a watch and a jar of coins.

"I wasn't too upset about the things that were taken because they could be replaced," said McKinney, 23. "What really upset me was somebody had been in my apartment that I didn't know. I just felt like my privacy had been invaded. I felt very strange."

McKinney said when she learned that police had arrested juveniles in connection with her burglary, "I didn't know what to think. How could parents let their kids do this?"

Washington said his apartment was broken into again a month later, and a $93 tape recorder was taken.

There was no sign of forced entry into his apartment. And though Washington said he knows who did it, police have been unable to close the case because they don't have any proof.

Despite the two burglaries, Washington said he plans to remain in the complex. "I'm not going to let them run me off because I can't afford to move right now. Besides, I just think you have to make a stand. Let people know that you're not going to run . . . ."

Washington like some other Stanton Hill apartment dwellers, says the police do not provide adequate protection against burglars.

"Up on Capitol Hill, they got police all over the place," Washington said. "They figure if they catch somebody breaking into an apartment or a house, they will make the newspaper, make the police look good. Officer so-and-so grabs person breaking into senator so-and-so's house. Here, they come and they check but they don't do a thorough job."

The 7th District's Kelly said the police are very concerned about burglaries in Anacostia. He pointed out that two police officers were killed in June when their helicopter crashed while pursuing a burglary suspect there.

"Burglaries are our top priority," he said.