Just before Miles Alban, the night sergeant on duty at Montgomery County police headquarters, went home last Tuesday morning, he made a prediction.

"I said, "I'm telling you the big one's going down today,'" he remembers. In fact it had gotten to be a joke around the Gaithersburg station. For the beleaguered detectives, the thought of "a big one" -- a big murder -- on top of an unusually heavy caseload seemed too farfetched to believe.

At 11:25 a.m., however, that prediction came true. Ali Akbar Tabatabai, an Iranian exile leader, was gunned down in the doorway of his Bethesda home, causing an international uproar and launching an investigation that over the next 24 hours would involve more than 100 local and federal law enforcement officers.

Lost amid the publicity and furor of Tabatabai's slaying was a startling statistic for the week that would end last Sunday: It was perhaps the most murderous seven-day period in the history of Montgomery County.

Besides Tabatabai, three other persons were murdered during the week and the death of a fifth person was listed as a possible homicide.

"I can't remember a time when we've had more homicides so closely grouped together," said Lt. Col. Wayne Brown, a county policeman for 25 years.

By the standards of many cities, the slaying of four and possibly five persons is almost routine. But in one of the nation's most affluent commuinities, where there were 18 violent deaths in all of 1979, last week was a remarkable and jarring departure.

Aside from the Tabatabai case, none of the deaths generated more than a minimal amount of publicity. The people involved -- ranging from a talented curator at the Smithsonian to a Gaithersburg teen-ager -- had nothing in common.

It was, in fact, a week that provided telling evidence of the random nature of violence.

"The ambassadors and the dirt bags all stand in the same shoes," said one weary investigator, adding: "That's not to imply these other victims were dirt bags. But all the cases are beinginvestigated with as much vigor as Tabatabai."

What follows -- based on interviews with police and friends and families of the victims -- is an account of Montgomery's bloody week of July 20 - July 27.

Alfred Steck, 27, used the elevator perhaps twice in the two years he lived in his high-rise apartment building in Silver Spring, a good friend, Rob McCurdy, remembers. It was usual for Steck, who parked his silver Grenada in the residents' parking lot, to walk the six flights up the back stairway to his apartment.

But at about 11 on the night of July20, a resident in the lobby of the Wayne Manchester Apartments pushed the elevator button, the door opened and there lay Steck's crumpled body.

Steck, a sculptor, had been shot in the chest at close range. He apparently was a mugging victim, police believe, because the worn brown leather wallet he always carried was not on him.

McGurdy, a former classmate of Steck at Virginia Commonwealth University, thinks Steck -- over 6 feet tall but slender -- might have resisted his attacker, or attackers. Police said, though, that the physical evidence shows no signs of resistance.

Steck worked in small figures -- sometimes only a quarter-inch high -- and although he didn't turn his attention to sculpture until after high school, he had always been good with his hands.

"His hands would almost think in terms of manipulating tools, whether it be for auto mechanics or for working with a fine piece of wood," said his father, Dr. E. A. Steck of Silver Spring.

At the International Sculpture Conference last June, Joan Mondale, the vice president's wife, asked Steck to see some of his work. Steck pulled a piece of his art out of his pocket.

He was a fan of Edward Gorey, an illustrator who lends a morbid touch of humor to his work.

"Just a little macabre," McCurdy said. "Ali had a really dry sense of humor, and his work was all puns."

One depicted a few little men climbing rocks on a very tall mountain with a nun peering down at the climbers.

His attention to the smallest detail obtained Steck his most recent job as a curator of special items for the Smithsonian.

The Friday before his death he had been leading a Smithsonian Associates critiquing tour in Philadelphia, and the next day he spent casting molds at his parent's house. On Sunday he had helped some friends restore an old house. When he was founmd in the elevator, at 11 p.m., it is not known where he had come from or was going to.

Some residents reported seeing two men fleeing the building about 10:30.

Wednesday is payday at Pel-Burn Electric, an electrical engineering contracting firm in Rockville. It was also the last day Allen Snowden showed up for work.

On Monday, July 21, Snowden was found floating face down in a Rockville creed with his pay stub in the pocket of his blue cutoffs.

A father and son, who had gone to the creek to cool off, discovered the body and reported it to police.

At first the medical examiner, Dr. Ann Dixon, who performed the autopsy, couldn't determine if the 26 year-old man was black or white. And the time of death wasn't placed more specifically than sometime between Wednesday, July 16, and Friday, the 18th.

Snowden was found with his hands bound. Police reported that "multiple trauma to the head with a blunt object" was the probable cause of death.

When Snowden didn't show up for work Thursday and Friday, his boss, Otis Megginson, wasn't concerned because in the two months Snowden had worked for him, he had missed work before.

"He was an okay worker," Megginson said of Snowden, who was an electrician's helper at the Exchange Office Building construction site in Rockville. "He was a quiet, ordinary kind of person; I didn't really take any notice of him."

Snowden lived with Carl F. Ruths at 300 Woodland Rd. in Rockville. Ruths has been charged with the murder in the case, and is free on $25,000 bond.

The house, according to neighbor, has been a home to many of Ruth's transient friends. "This is a quiet, family neighborhood," one resident said, "and they were noisy and single."

Another neighbor said she hasn't noticed a lot of people coming and going in the last few weeks, but that before Snowden's death "every day there was someone different staying at the house."

Of all the people who were slain in the week of July 20, only Ali Akbar Tabatabi, a prominent Iranian exile and unswerving foe of Ayatollah Ruhollah Khomeini, was known to police in life as well as death. He had called police on at least two occasions to report "numerous" threats against his life.

The killing "was the big one" detectives had talked about. For the police it was when the week took on extraordinary proportions.

With the help of advance intelligence work, the suspects were identified within hours after the assassination. By Wednesday afternoon two persons were already in custody and the FBI was spearheading a manhunt for the alleged triggerman.

Then there was another call.

When Patty Carey, 38, and her brother, Jim, 40, left their Silver Spring home last Wednesday morning, their mother Margaret Rose Carey, was asleep on the living room couch. When Patty returned home alone seven hours later at 3 p.m. her mo ther was still on the living room couch, but she was dead. Patty Carey called the pastor of her church, who called police.

Montgomery County police say Margaret Rose Carey's death is of "suspicous" origin. Together with the state medical examiner, they are trying to determine whether she died of the bruises all over her body, of a heart attack, of the emphysema she had been suffering from, or some combination of all three.

Carey, 65, had received the bruises several days before her death, according to police, but they haven't determined how she received them. The medical examiner expects to get results from toxicological tests on the body in several weeks.

Neighbors say that once Carey was an outgoing, happy woman who often chatted with them -- about the new dress she had purchased or her garden or her children. Her husband, Jim, was a CIO union official and occasionally the couple would be invited to the White House for social gatherings when Franklin Delano Roosevelt was president.

"She'd come over here and show me the dress she was going to wear to the White House," said one neighbor, Hazel Hurwitz. "She was one of the most beautiful women I ever saw. She had black hair, black eyes, a beautiful figure and she walked like she was dancing."

But Margaret Carey changed somewhat in the late 1940s, when her 8-year-old Patty was hit by a car. Her daughter lay in a coma for a month and developed a learning disability as a result of the accident.

"Marge never was the same after that accident," said Hurwitz. "She used to love to take my son and Patty to lunch, do things like that, but after the accident she was less interested in everything."

After her husband died in 1972, Carey lived with her two children, but she became a recluse. She gained a great deal of weight, neighbors say, and she hardly ever left her red brick house at 8 Hilltop Rd.

Craig Eugene Grant of Gaithersburg had just graduated from Magruder High School and was looking forward to going to Montgomery College on a football scholarship. Then last Sunday, in a wooded area near Fairhaven Drive in Gaithersburg, he was stabbed to death.

Grant's 17-year-old cousin, Cornell Lee Duvall, was arrested and charged as an adult with first degree murder in the stabbing. He is being held without bond.

Police say there was "bad-blood" between the two, but will not release details of the argument that led to the stabbing. Grant's father, Rayfield, said Grant and his cousin "had always been good friends."

From the time Grant was youngster, he had wanted to be a professional football player or basketball player. He was a guard on the football team at Magruder and played center for the basketball team at Gaithersburg Junior High School. When he wasn't practicing with his team, he'd be at the recreation center in Gaithersburg playing basketball or football.

Around 1 p.m. Sunday Craig and his 22-year-old brother Donald got in Donald's car and drove to Emory Grove Park in Gaithersburg. While Donald washed his car, Craig sat on the roof of another car talking to friends. "I told him I was going to a freind's house and that he should wait till I got back and picked him up." Donald said.

But instead of waiting for his brother to return, Craig walked a few blocks to his cousin's house. In a wooded area near his cousin's house, the two had an argument, police said. During the argument, Craig Grant was thrown to the ground and stabbed repeatedly in the chest, police said.

"He was just a quiet boy," said a neighbor, Diane Smith. "I don't know why anyone would kill him."

The four homocides and possible fifth were not the only violence in the county during the week. In addition, there were four suspicious deaths, two sex offenses, two armed robberies, one aggravated assault that left a couple of Olney residents in critical condition, one drowning and one accidental shooting.

For the police, it meant seven long days.

In the middle of the week the detectives who handle homocide cases borrowed a bigger coffee pot from the burglary squad. Some smoking habits jumped to four and five packs a day. Some investigators ran out of lunch money because they could never get to the bank. As it was the days ran together and most of the meals they seemed to eat no matter what time of day or night were breakfasts.Or carryout pizza.

Bloody shirts, guns, sheets and future state exhibits piled up in the room where evidence was stored and under the detectives' desks until there was no more room for their feet.

To the police, why this particular week should have been so violent is a mystery.

"I don't even try to explain why," said Lt. Col. Brown. "A lot of people put stock in the full moon theory. But there'll be worse weeks. Society doesn't seem to be getting any more pacifistic. The chemistry was right and people just took each other's lives."