Once during the TRICONN operation, two undercover police officers were caught in their own trap. They were trying to sell "stolen" leather coats to thieves: instead the thieves stuck a sawed-off shotgun in their faces and held them up.

It happened on a Southwest street last Nov. 26, and almost marked a tragic and premature end to the udercover operation.

"Hey, don't point that shotgun at me," undercover officer John O. Lewis protested when one of the thieves opened his trenchcoat and pulled out the weapon.

"Man," said the armed robber through clenched teeth, "don't tell me . . . what to do . . ."

The robbers, convicted burglars out on probation, demanded everything. "Wallets, Wallets," one said excitedly, waving the shotgun. "Take off your watches . . . Do anything funny and your . . . head is gone."

Lewis and his partner, John W. Feather Jr., both inexperienced at undercover work were saved through the surveillance of other policemen, who charged their van and began firing. The thieves themselves were saved only because another police man, firing shotgun blasts at them, missed his mark.

The shootout developed into a two-hour siege of an apartment building and eventually the surrender of the holdup men.

Shocked police officials suspended TRICONN for several days following the shootout, and considered canceling the project altogether.

Police officials put out an intentionally misleading report of the incident in the press, referring to it as a bungled drug transaction. They finally decided to go ahead with the operation after it became apparent that undercover officers were still being contacted by thieves.

Now that the operation is over, a description of this shootout can be presented in unusual detail. Evidence gathered by prosecutors, including a tape recording of the conversations leading up to the shootout, give a clear indication of the tenuous balance between police and their prey.

The two thieves pleaded guilty to armed robbery earlier this year.

The tape reveals how the officers contributed to their problems by sounding more like department store salesmen than street hoods. It also reveals, in chilling tones, the threats of men who say they would not hesitate to kill.

Feather and Lewis, dressed modishly and purporting to be hoods, were showing cartons of new "stolen" leather jackets to street thieves in hopes that they would be led to big-time fences. If all went well, they could make a sale, find the bigger fences, and entice them to return to the operation's warehouse in Northeast, where there were large quantities of "stolen" merchandise - and hiden videotape cameras.

Shortly before 4 p.m., the two officers pulled their van up to 39 O St. SW, on the fringe of housing projects, for a prearranged meeting with a would-be buyer.

One of the robbers approached the van and began talking; the other, armed with a shotgun, waited out of view, apparently to see how things developed.

"Let me hold your coat," said one of the undercover officers. "Why don't right size for you."

"It's all right - I ain't gonna try it on," the customer said, sizing up the van.

"I kinda like this blue one right here," said one undercover officer. "I like the lines - this is what? A 40? Why don't you go ahead and try it on, make sure that's the right one . . . fits you right."

"It's all right," the customer said, casting a glance over his shoulder.

More experienced undercover men have since explained that it is essential that control is established in these situations because street-wise people who hear this kind of amiable talk react like sharks to blood. Other undercover officers in the TRICONN operation cursed freely, pointed guns at customers and occasionally threatened to throw them out of moving vans.

"You know anybody we can go to (who will) handle a lot of stuff?" one of the policemen asked. The robber hesitated.

"Well, if you don't want to deal with us . . . if you're afradi fo us, you . . ."

"No, if I was, I wouldn't be here. You know I'm not afraid of you all. You know, I can take this off your hands man, but, you know, as far as what you get next time, I don't know, we'll have to talk about that."

"Don't you know anyplace we can unload everything?"

"I don't know. Maybe my brother, man . . . I can take some of the goods off your hands . . . like I can't promise to deliver anything you get . . . 'cause my connections ain't that great, you know. Like I'm just trying to make you know, a buck or two for Christmas. . ."

The men haggled over prices for a few leather coats. "They sell for 300 bucks," said one officer. "Woodies is getting some of these, too - genuine leather . . . Smell it - it's got a good smell."

They agreed on a price when the second suspect, wearing a trenchcoat moved toward the van. The undercover offices handed over a leather jacket. Don't tell anyone where you got it, right?" one of the officers said.

"Oh no, man," was the reply.

When the robber produced a shotgun, the undercover policemen quickly lost the color.

"Back it up, in the back, get in the back," the armed man yelled.

"Yes sir," Festher said.

The robbers took money, a watch and a wallet from the men and were examining Lewis' .38 caliber police service revolver.

In an unmarked cruiser nearby, Det. Patrick J. Lilly monitored the conversation. Although music played in the van, the FBI had installed microphones that filtered out the music but taped the conversation.

Another undercover man watching the van, George Green, approached, trying to distract the robbers. From a distance he began shouting for a screwdriver.

The robbers, fingering the police special, concluded they were dealing with policemen, and that they themselves were now in the trap.

"Pop the door. It's the rollers (police)," one of the robbers said.

Lilly, racing toward the van, began firing his shotgun. The first blast hit a corner of a three-story, red-brick apartment building at 39 O St. SW, and the men ducked inside. Green, dressed in street clothes, fired two shots from his service revolver.

Lily's next shot pierced a radiator just inside the apartment entrance. As the robbers scrambled up the staircase, slipping on the radiator water, Lilly's subsequent blasts went over their heads.

The two robbers fled to a third-floor apartment and held three people hostage for two hours, until police on the telephone persuaded them to surrender.

The two men were identified as Dwayne Dark, 25, of 133 Galveston Pl. SW, and Andrew Dean, 25, of 4345 Martin Luther King Ave. SW. Earlier this year in D.C. Superior Court, the men were sentenced to prison for armed robbery - Dean from 6 to 18 years, and Dark from 4 to 12 years.