Shortlt after one o'clock this morning, at least one terrorist broke into an official guest house where I was staying in the heart of Phnom Penh and shot and killed Malcolm Caldwell, a 47-year-old British scholar and journalist.

It was the last night of a two-week visit to Cambodia by Caldwell, Richard Dudman of the St. Louis Post-dispatch and me. We were the first noncommunist Western journalists to travel in this country since 1975. We had traveled more than 1,000 miles, shared all our lodging and meals, and spent our last evening together at the guest home on Monivong Avenue in the government compound near the old presidential palace.

Caldwell, lecturer at London University's School of Oriental and African Studes, said goodnight around 10:30 p.m. and retired to his second floor bedroom across the hall from Dudman. I went to my room on the first floor just off the dining room.

Three hours later, a terrorist shot his way into our house, threatened me with a pistol and shot at Dudman three times, missing him entirely. He then killed Caldwell at point blank range, Cambodian officials said. It is still not completely clear, but the gunman apparently had two accomplices who remained outside the house.

Although Caldwell was killed around I a.m., Dudman and I wrre not freed from our rooms until three hours later.

Deputy Prime Minister leng Sary and the murder was an act of political assassination meant to "discredit" Cambodia.

Asked how the terrorist and the two reported accomplices were able to break into our compound past three armed guards and sentries from the nearby government palace, the minister could not answer. Nor could he or any other official tell Dudman or me why we were left to fend for ourselves for nearly two hours inside the house while at least one intruder roamed the yard. Even after government forces arrived, we were still shut in our rooms for almost an hour.

This morning, when I firt heard gunshots, I was taken aback because our trip had been so quiet.

In the cities and the countryside of Cambodia, we had seen almost no evidence of a military presence, except on one trip we took to the border region with Vietnam. There were few weapons visible among our guards. Rifles or pistols were rare at government checkpoints.

I had fallen asleep last night about 11:30 p.m. and woke instantly when I heard what sounded like a loud crash in back of the house. Immediately, I heard a much closer sound, like a shot from a pistol, followed by a low murmur.

I jumped out of bed and quickly put on my clothes. The acrid smell of gunpowder came through my door. I opened the door, switched on the lights and went out into the dining room where I practically ran into a young man. Immediately, I took him to be a stranger.

He was wearing a black T-shirt, which I had seen no one wear in Cambodia. His hat was not a Mao cap, but more closely resembled the baseball cap worn by the American military.

He was heavily armed. A band of ammunition was strapped around his chest, a rifle was slung over his left shoulder, and he held a cocked pistol.

We looked at each other. I remember that he looked more frightened than I felt. The he pointed the pistol at my face and I screamed, "No, don't."

In seconds, I had run back into my bedroom, closing the door. Then I ran into the bathroom and closed the door. First I crouched in the bathub and waited.Over my head on the stairwell, I heard rubber sandals running up to the second floor. At least three loud shots rang out over my head. I moved to another part of the bathroom, away from the window, and sank to the floor.

During my confrontation with the gunman, Dudman and Caldwell were apparently upstairs listening to what Dudman later said was a racket of gunfire. Dudman said he had gone out onto the second floor balcony when he first heard three or four gunshots. He said he saw men running back and forth in an alley between our house and the neighboring house.

He went from the balcony back to the bedroom hallway and knocked on Caldwell's door, telling him to turn out his light and stay in his room. Before Dudnam could reach his bedroom, he saw a gunman, apparently the same one I had met, standing in the hall and pointing a pistol at him. Dudman said he thought the gunman was friendly.

Even when the man shot at Dudman, Dudman still thought he was a friend trying to shoot someone outside the house, Dudman said later.

He took this as a warning, however, and went back into his bedroom, closed the door and stepped ot one side of it. Two shots were fired through the door. Dudman said he then crouched on the floor alongsid his bed.

From my bathroom hideaway, I heard someone run down the stairwell across the living room and outside to a car. I heard a car engine start, and then there was silence.

Dudman, wearing two wrist watches, kept track of the time. He calculated that it was one and one-half hours from the moment of the final gunshot he heard until the crash of glass on the first floor that signaled our apparent rescue.

The only sound I heard during that time was spoken commands. I speak very little Khmer but I could distinguish voices saying yes and no. I heard the sound of footsteps running around the house. After the glass shattered, a great noise came from the stairwell. It sounded as if something heavy was being pulled downstairs. I heard new voices in the dining room and someone walked into my bedroom. Then th ebathroom door opened. It was La, an official I kenw from my trip. He told me everything was fine, but that I could not leave my room.

Forty-five minutes later, at about 3:45 a.m., Thiounn Prasith, the highranking Foreign Ministry official who was our guide during most of our visit to Cambodia, came in and told me that Malcolm was dead.

The official's face was stricken but he tried to comfort me. He brought Dudman downstairs so that I could see he was alive. Then he asked Dudman and me to view the body. We climbed up the stairs and I saw a man who looked like the gunman lying dead across the threshold of Caldwell's room.

Inside, Caldwell was laying next to his bed. His face was ashen and there was blood on his chest and leg. He was dressed, as if he had been awake for a while before being shot.

After a very few moments of comforting one another, Thiounn Prasith asked us to bundle up our belongings and move to another home down the block. Quickly, we obeyed.

Neither Dudman nor I could sleep. We stayed close to each other waiting for sunrise, unconvinced that what we had seen could not happen again.

Sometime about noon, Thiounn Prasith returned and told us that one of the accomplices had bee captured and another had escaped. He said that government soldiers had tried to rescue us and that two of the house attendants had been wounded.

An investigation was under way, he said, to determine if there was a need for additional protection. He also said that no identification had been made of the gunman who allegedly commited suicide.

Around 1:30 p.m., we were driven back to the scene of the attack. There, Ieng Sary met us and ushered Dudman, Thiounn Prasith and me into the house where Caldwell had been laid to rest in a casket. Flowers flanked the coffin. We all paused for a moment of silence.

Once again, Dudman and I were asked to view the body, so concerned were the Cambodian officials about verifying his death.

Ieng Sary told us that on Friday afternoon, Caldwell had had an interview with Prime Minister Pol Pot, which had ended with Caldwell promising to try to improve British opinion of Cambodia. Pol Pot had assured Caldwell that he could return to Cambodia.

We watched as the casket was loaded onoo a small military truck. In a caravan, we went to the airport for the afternoon flight to Peking. It was the flight we had been scheduled to leave on originally and was held at the airport today so the small ceremony at the casket could be completed.

Caldwell, a Marxist economist who had written favorably of the Cambodian Communist administration, had been treated throughout our stay as a special friend of the government.

Although the Cambodians referred to Caldwell only as a friend, he was also a well known scholar of Southeast Asia. He was writing a book on Cambodia's radical agriculture policies and was the coauthor of a 1973 book entitled "Cambodia in the Southeast Asian War." He was also an often humorous critic of Cambodian communism. During our travels he would laugh at left-wing notions that Cambodian peasants sing while they harvest rice.

"Nobody can sing in those bloody rice fields," he said.

He loved to cry out, "Where are thosed armed guards oppressing the peasants?" as we passed mile after mile of rice fields with no guards in sight.