About 3 a. m. last Oct. 28, metropolitan police Officer Jerry F. Denton entered a Cadillac in front of the Cats Pajams massage parlor on 41st Street NW agreed to accept bribes to "protect" the parlor from being raided.

He put the first payment of $100 inside his uniform pants pocket. By last Friday, he had collected $2,900 - usually in $50 weekly payments, but including a $1,300 "bonus payment" for special information he had provided.

Last Friday, he was in the parlor when a squad of police officers raided it and arrested the owner and a 19-year-old masseuse. They also appeared to arrest Denton.

Instead, unknown to the other persons arrested, Denton had been an honest officer all along. He had told his superiors about the alleged bribe scheme from the start, and had turned over the "bribe" money to them.

Officer Denton's well-played role as a rogue policeman surfaced in an affidavit filled in D. C. Superior Court for a search warrant and arrest warrants for four persons in connection with the bribe scheme.

According to the affidavit, the message parlor owners told Denton they were attempting to shift their location of a string of massage parlors to D.C. from the Baltimore area because they were having difficulty with the police there.

One of the defendants said he thought Washington "to be easier than Baltimore on the total enforcement picture of massage parlors prositution and other related enterprises," according to police internal affairs Officers Peter J. Mulligan, who signed the affadvit.

Investigators said the bribe-taking drama was played out for such a long period because of the apparent attempt to organize massage parlor owners here, and to see if there was any indication of a more widespread corruption attempt.

Some of the conversations between Denton and the parlor's owners were secretly taped by the officer, investigators said. However, he did not wear the hidden recording device on the occasion after another unrelated bribery arrest by a policeman was announced here. The owners of the parlor searched him on that occasion - and that occasion only - the investigators said.

According to the affidavit, Denton was first approached with a bribe offer at the massage parlor on May 23, 1976. Denton reportedly was making routine rounds there when he was approached by William M. Larson, the manager of the parlor.

The affidavit said Larson, 32, of Linthicum, Md., asked Denton about the arrest of one of the massage parior's employes on a prostitution charge and offered him $200 to see if he could get the case dropped. Denton turned down the money, according to the affidavit.

After informing his superiors on the police force, Denton kept talking with Larson and was ultimately introduced to Charles Ephraim Elmore Jr., 43, of Glen Burnie, Md., one of the parior's owners, according to the affidavit.

The first actual bribe payment came after Denton and Elmore met in Elmore's Cadillac last October, the affidavit asserted.

The affidavit also told Denton met with another owner of the parlor, Gary Maynard Shoemaker, 27, of Pasadena, Md., and discussed the bribe payment with him.

On another occasion, according to the affidavit, Denton received a $150 bribe payment from a message parlor employee named "Angel," who removed the money from her undergarments to give to the policeman.

"Angel" later was identified by authorities as Melissa Darlene Blankenship, 19, of the massage parior at 4617 1/2 41st St. N. W.

Blankenship, Elmore, Shoemaker and Larson all were arrested on local bribery charges and released on $2,000 bond, according to Assistant U. S. Attorney Charles Harkins Jr., of the major crimes divison.