Montie Ralph Rissell, accused of killing five Northern Virginia women, testified in court yesterday that he confessed to the slayings on two occasions because police told him he was sick and promised to help him get psychiatric help.

Rissell said at a pretrial hearing in Alexandria Circuit Court that Fairfax County and Alexandria police led him to belive that he would not be prosecuted if he helped them solve the slayings.

Police testified at the same hearing that they made no promise to Rissell.

Circuit Judge Donald H. Kent heard the testimony in response to a defense motion to suppress the statement Rissell made to police and the search warrants that police used to get evidence in the case. The judge scheduled arguments on the motion for Aug. 18 and indicated he will rule then. Rissell's trial is scheduled for Oct. 3.

Rissell testified that as he made a statement to police May 17, Fairfax County police investigator Colin J. Kozloff "started a sermon about if there's a sick dog you don't just kick it in the head. If there's a sick person you don't keep medicine away from him."

Rissell said that at another point in his interview with police Kozloff said, "Remember what I told you about the sick dog and medicine?"

"Whatever you do we're here only to help you," Rissell testified the police told him. "I believe they thought I had something to do with these crimes and they wanted to help me."

Rissell said police told him "no (terminal) action would be taken because they told me I was a sick person.

Kozloff and four Fairfax County and Alexandria police testified earlier yesterday that they made no promises to Rissell. Kozloff said he did tell Rissell, "If someone gave a person medicine for a cold to throw it away, it wouldn't help him." Kozloff said he did not tell Rissell anything about a dog and he did not tell Rissell he would try to get him psychiatric help in a hospital.

Rissell testified calmly in a deep but sometimes barely audible voice. He smiled twice when questions posed by Assistant Alexandria Commonwealth's Attorney T. Rawley Jones were overruled by Judge Kent.

According to police testimony, Rissell was arrested at his home May 13 on a felonious assault charge stemming from an incident at a party. Rissell gave police a statement about the incident, then the police took a break, the testified.

They said that when they returned they asked Rissell about the slayings of Ursula Miltenberger, whose body was found last March in a Fairfax County field. Rissell denied killing her or the four Alexandria victims, the officers testified.

On May 17, Alexandria police obtained search warrants for the 1969 Ford Torino Rissell drove, but which was titled in his mother's name. Defense attorney attempted to show that the search warrants were improper because police had failed to get IRissell's consent to search the car, only his mother's.

Police testified they found a knife in the front seat and a wallet, belonging to Aletha Byrd, one of the victims on Airo comb and keys in the car trunk.

Alexandria investigator John W. Turner testified that after taking photographs of the items in the car, he told Rissell what evidence had been gathered.

Rissell "explained he didn't know how it [the evidence] got in there," Turner testified. "I told him it was time to cleanse his soul. At that point he said, "I did it." Another policeman asked Rissell, "All of them?" Turner testified. Rissell then said, "Yes." Turner said.

Rissell was indicted May 20 on 12 counts of murder, rape and abduction. Turner testified that on the following day Risssell agreed to take him on a take him on a tour of the alleged slaying scenes.

The suspect did not hestitate during the "walk-through," Turner said, and discussed "each case individually." The "walk-through" was videotaped and tape recorded by police, the officer testified.

Turner said he then received a permission from Rissell to search the apartment where he lived with his family, and the search produced a water, later identified as that of Jeanette McClelland, another of the dead women.

Turner also said he had Rissell under surveillance since August, 1976 when the first slaying occurred, because he "had a gut feeling" about Rissell.

Rissell is charged in the slayings of Miltenberger, Byrd, McCleeland, Aurua, and Gladys R. Bradley. Four of the women lived in the same area of western Alexandria and the fifth, Miltenberger, worked at a restaurant near that area.