A District police detective testified yesterday in D.C. Superior Court that Paul Leon Jordan, in statements punctuated with tears and fits of trembling on the night he was arrested, told him that he had stabbed Cora Barnes and 3-year-old Crystin Fletcher after the child's cries interrupted his and Barnes' lovemaking.

Jordan, a 47-year-old Northwest Washington man, is charged with murder in the Jan. 24 deaths of 56-year-old Barnes, who was baby sitting with Crystin, the only child of two District police officers.

The detective's testimony came in a hotly contested pretrial hearing over whether the alleged statements -- which both sides agree are crucial to the prosecution's case -- may be used as evidence in the trial. "The confession is the heart of this case," said prosecutor Amy Berman at the hearings Tuesday, "and the confession is hotly disputed."

Defense attorneys are asking that Jordan's alleged statements to police be suppressed, arguing that they were taken in violation of his constitutional rights and are unreliable because he was suffering from serious symptoms of alcohol withdrawal during the police interrogation. "We'll prove [Jordan] was in a state of medical disability when he talked to police," defense attorney James McComas said in court.

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

Yesterday, detective Joseph Schwartz testified that during an interrogation on Feb. 14 Jordan first denied a friendship with Barnes, who lived next door to him at 4321 Second St. NW. Schwartz testified that Jordan later said he had "a sexual relationship" with Barnes, often went to her home and knew Crystin, whom Jordan called "Little Sweetheart."

"He liked the baby a lot," Schwartz said Jordan told him. "He'd play with the child, bring candy over, put the child on his knee."

First, Jordan told him several times that he had been at Barnes' home on Jan. 24, watched soap operas and then left, Schwartz testified. But then, Schwartz testified, he displayed photos of Barnes and the child and told Jordan, "Till we know the truth, Little Sweetheart and Mrs. Barnes can't go to heaven. We need to know the truth . . . . "

Then, according to Schwartz, Jordan told him that on the day of the slayings, he and Barnes "made love" on the bed where the child was sleeping. The child started to cry, and Barnes, then angry at Jordan, went to comfort the child, Schwartz quoted Jordan as saying.

Schwartz testified that Jordan told him he "grabbed the baby around the throat . . . and choked" her, while Barnes tried to stop him. Then, according to Schwartz, Jordan said he got a butcher knife, struggled with Barnes and stabbed her.

Schwartz said Jordan told him he then returned to the child's room and sexually molested her.

"I asked what else happened," Schwartz testified. "He had tears in his eyes . . . . It appeared he was trying to tell me. His mouth was moving, but nothing was coming out."

But after Schwartz prodded him, according to the testimony, Jordan said he "stabbed [the child] in the throat to make sure she was dead . . . . He had to do it. She knew him and would tell on him."

At one point during Schwartz's testimony, the child's father, Cortez Fletcher, stepped into the courtrooom and stood staring at the witness. Another spectator called out his name and rushed to take him back outside, with the help of a U.S. marshal.

Because he is a potential witness in the case, Fletcher must remain outside the courtroom.