The government prosecutor in the Abscam bribery trial of lame-duck Reps. Frank Thompson Jr. (D-N.J.) and John M. Murphy (D-N.Y.) told the jury today that common sense and the FBI's videotapes proved that the two men accepted $50,000 cash payoffs.

In his closing argument, Thomas P. Puccio said the veteran congressmen "knew what was in the briefcases" that middleman Howard L. Criden carried from separate meetings with undercover agents in October 1979. Puccio said it was implausible that the defendants were "taken in" by Criden, as their lawyers claim.

"Pay attention" to the videotapes, Puccio urged the jury. "Look at the expressions, the movements, even the silence."

Thompson's lawyer, Stephen Kaufman, said the government had not traced "one penny of Abscam funds" to Thompson. Kaufman called Criden a "bounty hunter" who "misrepresented" Thompson to the agents and misrepresented the intentions of the agents to Thompson.

Defense attorneys contended throughout the trial that Criden walked away with all the money. Thompson said on the witness stand that he thought the briefcase at his Oct. 9, 1979, meeting in Washington contained immigration forms. Murphy did not take the stand to testify about the briefcase Criden picked up at the Oct. 20, 1979, meeting he attended at Kennedy airport in New York.

The jury is expected to begin deliberations Tuesday.

Puccio dismissed Thompson's explanations of the transaction as "ridiculous." In the first of two meetings on Oct. 9, Thompson said "well, I'm not looking for any money" when undercover agent Anthony Amoroso raised the subject of paying for immigration help for a fictitious Arab sheik.

The 62-year-old Thompson, chairman of the House Administration Committee, used "careful language, the type one would use to cover himself," at the first meeting, Puccio said. "Mr. Thompson went back for some unfinished business; $50,000 is why Mr. Thompson went back to pick up the suitcase."

Thompson said he returned to the house in Washington solely to discuss investments in his district. "Is it logical that of all the places in the world, that Trenton would be selected as the repository of the sheik's money?" wPuccio asked.

Of the tape of Murphy, the 54-year-old chairman of the House Merchant Marine and Fisheries Committee, Puccio asked the jurors: "Is that a man who doesn't know what's going on? Is that a man who doesn't know what's in the suitcase?"

During the trial, Murphy's attorney, Michael Tigar, emphasized a tape made in January 1980 in which the congressman told Amoroso that he hadn't and wouldn't take any money.

On the tape, the surprised Amoroso laughed and told Murphy, "I, you're play . . ., you're being coy with me . . . ," and said he'd been reluctant to give Murphy the money because he had been so cautious that day in October.

"You didn't, you didn't give me any money," Murphy replied. "I never received any money from anyone . . . and would not accept anything."

Puccio countered that Murphy only said that because he had become suspicious of the "sheik's" representatives.

Because both defendants said at least once on the secretly recorded videotapes that they weren't interested in money, and because none of the payoff was ever traced to them, Puccio has had to build a circumstantial case. p

He showed that Thompson was making and paying back loans with $100 bills a few weeks after the alleged payoff. He also introduced some evidence of cash expenditures by Murphy.

Thompson seemed to be hurt by testimony from Rep. John P. Murtha (D-Pa.), an unindicted coconspirator who testified that Thompson approached him on the House floor last year and said he could get $50,000 in "walking around money" for meeting with the "sheik's" representatives. Murtha met with the undercover agents in early January, but refused overtures about money. Thompson testified he never mentioned money to Murtha.

The evidence against Murphy was less direct. As Tigar said to U.S. District Court Judge George C. Pratt one day when the jury was out of the room: "Putting it crudely, nobody puts the green in his [Murphy's] hands and nobody shows that he ever saw the green."