A written confession in which Lon A. Lewis described a "you-kill-my-wife, I'll-kill-yours" plot that allegedly led to the murders of his wife and daughter by another man was read to a Prince George's County jury yesterday.

The admission of the confession into evidence at Lewis' trial over defense objections that it was involuntary came after police testimony that Lewis had undergone extensive testing and questioning before making it. Cpl. T.R. Tucker of the county police homicide squad testified he took the statement after identifying himself and telling Lewis,"... you've inconvenienced my men the last few days with this. It's all over. You killed your wife and child and you can't deny it. You can't change it."

Lewis, 28, is on trial in Prince George's Circuit Court charged with conspiracy to commit murder in connection with the Sept. 23 stabbing deaths of his wife Carol and their 4-month-old daughter Heather. Both were found in the kitchen of the Lewis home in Bowie.

Gene. T. Meyer, 28, was convicted of murders in both slayings April 27. The two men both worked for Data-Point Corp., a computer firm and allegedly began discussing the idea while at training sessions in San Antonio. Lewis has admitted he was having an affair with a woman there during the months before the murders.

In court yesterday, Cpl. Earl Jones, the technician who administered polygraph tests to Lewistestified under cross-examination he spent three-and-a half to four hours, accusing Lewis of the murders during a 12-hour session on Oct. 6, the day before Lewis was arrested.

Jones said that after asking Lewis the same set of questions on the poly-graph three times, which is "standard procedure," he examined the results and told Lewis, "there's something wrong here, we've got a problem." Then, Jones testified, "Iaccused him of doing it. I said 'You killed them.' He said Lewis denied this adamantly.

Asked by defense attorney Leslie Gladstone if he accused Lewis, "Over and over and over and over again," Jones said, "Yes sir, I did."

Jones said after testing Lewis and talking to him from about 1:30 p.m. on Oct. 6 until 1:30 a.m. on Oct! 7, he sent Lewis home even though Lewis wanted to take the polygraph test again after being told he was lying.

The next afternoon, Jones testified, Lewis insisted on taking the test again, and did so twice.

Jones said tests indicated that Lewis had not commited the slayings but that his answers to some questions were lies.

At this point , after Jones and homicide squad Cpl. Tucker had accused Lewis of murder, Lewis broke down and cried, saying, "I didn't do it, but I know who did. Gene Meyer did it, but I'm just as guilty as he is.I wish I was dead," according to Tucker.

Tucker said he then listened to an oral statement from Lewis, had him write it out and questioned him about it in detail.

Gladstone argued yesterday that the statement - referred to by both the defense and prosecution as a confession - was involuntary and therefore invalid.

In the confession, read to the jury by Tucker, Lewis said he and Meyer agreed to "be partners" in killing each other's wives. Meyer allegedly wanted to collect on a $100,000 life insurance policy.

On the night before the slayings, Lewis said in the statement, Meyer came to his home and was introduced to his wife and daughter.

"He told me he would have done it then if I hadn't been home." Lewis wrote. "He told me if I worked late the next day he'd take care of it.

"I called my wife at about 5 the next day because I had to work late. I was frightened. When I started home about 6, I hoped I could get there in time. Then I saw Gene's car with him in it and I knew it was too late."