Paul Leon Jordan, in an hour-long interrogation captured on videotape and played yesterday in D.C. Superior Court, told police "I lost my head" before stabbing Cora Barnes and 3-year-old Crystin Fletcher, the two victims he is accused of murdering last Jan. 24.

The small television screens set up in the crowded, stuffy courtroom of Judge Eugene Hamilton showed Jordan sometimes offering halting answers, sometimes responding with long silences and sometimes shaking so violently that he could hardly grasp the cup of water he was trying to drink.

Jordan, a 47-year-old Northwest Washington man, is charged with murder in the deaths of 56-year-old Barnes, a neighbor who was baby-sitting with Crystin, the only child of two District police officers. He has pleaded not guilty to the charges.

The prosecution and defense are locked in a heated battle over whether his statements, which both sides agree are crucial to the prosecution's case, may be used at his upcoming trial. Defense attorneys are asking that they be suppressed, arguing that they are unreliable because they were taken while he was suffering from serious symptoms of alcohol withdrawal and in violation of his rights.

The prosecution has denied their allegations, asserting that the statements were "voluntarily and freely given" after Jordan was advised of his rights.

Yesterday, under cross-examination by defense attorney James McComas, Det. Joseph Schwartz acknowledged that he had violated several police department written orders setting out rules for videotaped interrogations. Schwartz, according to testimony, failed to ask during the taping whether Jordan objected to the process, whether he had been "promised" anything in return for his statement and whether he was using drugs or alcohol.

Schwartz also acknowledged he lied when he told Jordan during questioning prior to the taping that he "wouldn't tell anybody" of their conversations.

"I don't think I told him it the statement wouldn't be used against him," Schwartz testified. "I told him it would be between us."

"That was a lie?" McComas asked.

"Yes it was," Schwartz said.

The detective, however, also testified that he advised Jordan of his rights to remain silent and have an attorney present just prior to the taping, and the tape shows him discussing a form that indicates Jordan has been told of his rights.

Jordan was asked to sign the form but was unable to because "his hands were shaking," Schwartz testified previously.

On the videotape, Jordan told Schwartz and another officer questioning him that he and Barnes started arguing after they had made love in the bedroom where Crystin was sleeping. Jordan said he "smacked" Barnes with his fist, Barnes fought back and then he went to the kitchen and got a butcher knife.

Crystin started crying during his subsequent struggle with Barnes, Jordan said in a series of brief, sometimes halting, answers on the tape, and he stabbed both of them. "The baby saw . . . so I had to take care . . . " Jordan trailed off during one answer. "How?" the detective asked him. "With a knife."

Under cross-examination, Schwartz acknowledged that Jordan's videotaped statement differed in several respects from Jordan's oral statement, which Schwartz described in testimony Thursday. He also acknowledged that on the tape Jordan made several statements about the crime, which, in McComas' words, Schwartz "knew could not possibly be true."