MILWAUKEE (AP) _ Jeffrey Dahmer told a psychologist he drilled a hole in the head of a Laotian boy and poured in acid before police encountered Dahmer and the naked, dazed boy on a sidewalk, the psychologist testified Tuesday.

The officers involved said they believed Dahmer when he told them the boy was his adult homosexual lover, and left them in Dahmer’s apartment. Dahmer has said he killed the boy shortly after police left.

Judith Becker, a defense psychologist, is the first witness in Dahmer’s insanity trial to indicate that police failed to notice a hole in the boy’s head.

But defense attorney Gerald Boyle said at a news conference after the testimony that police couldn’t have noticed the injury. ''There was no blood apparent from the boy’s head,’' he said.

A defense psychiatrist testified Monday that Dahmer used a drill to perform brain surgery on some of them victims in an effort to turn them into sexually pliant ''zombies,’' but strangled them when he realized they might leave.

The boy, 14-year-old Konerak Sinthasomphone, fled the apartment May 27 when Dahmer went to the store, but officers returned him when Dahmer convinced them the two had had a lovers’ spat.

The incident prompted critics to accuse police of insensitivity and discrimination toward homosexuals and minorities. Two officers later were fired.

Ms. Becker also testified that Dahmer got a sexual thrill from eating body parts of some of the 17 men and boys he admitted killing and dismembering.

''Periodically, he would take portions out of the freezer and cook them,’' Ms. Becker said. ''While he ate he would become sexually aroused.’'

Dahmer had sex, in one way or another, with all 17 victims after death, Ms. Becker said. Ms. Becker said Dahmer soaked one victim’s genitals and head in acetone to mummify them.

''Maybe I was born too late,’' Ms. Becker quoted Dahmer as saying. ''Maybe I was an Aztec.’'

The Aztecs had an advanced civilization in what now is Mexico before the Spanish conquest in the 16th century, and were known to perform human sacrifices.

Ms. Becker, a psychologist who teaches at the University of Arizona, said she interviewed Dahmer for more than nine hours over two days.

Dahmer told her he purchased a black table for a temple composed of his victims’ body parts that he said was for gathering energy, she said.

Dahmer put some victims on the table, positioned their bodies to imitate posters of men hanging on his walls and then took photos of the victims, Ms. Becker said during questioning by Boyle.

Ms. Becker said Dahmer suffers from necrophilia, a compulsion to have sex with the dead, and was unable to keep himself from killing.

She said Dahmer showed remorse for all of the killings and wanted to write letters of apology to the victims’ families.

''He stated he wished he could die, that his heart would stop beating,’' she said.

Earlier Tuesday, a psychiatrist who said Dahmer was sexually aroused by his victims’ body parts said during cross-examination that Dahmer dismembered the bodies primarily as a means of disposal, not for sexual pleasure.

''He didn’t want to get caught and this was a way of making sure he didn’t get caught,’' Dr. Fred Berlin said. ''But (the dismemberments) might be tied in somewhat to his disease.’' Berlin also said Dahmer suffers from necrophilia.

Prosecutor E. Michael McCann is seeking to prove Dahmer was sane at the time of the killings. Dahmer and his lawyers contend he was insane.

If jurors decide Dahmer was sane, he will receive a mandatory life sentence for each one. If found insane, he will be sent to a mental institution and after a year could request release every six months.

Berlin, a sexual dysfunction specialist at Johns Hopkins University, said he expected to receive about $10,000 for testifying on behalf of the defense. He said he examined Dahmer for about six hours.

Dahmer, 31, has pleaded guilty but insane to the mutilation slayings of 15 young males in Milwaukee County.

Dahmer confessed to 17 slayings after police found body parts of 11 males in his west-side apartment. He hasn’t been charged in one of the Milwaukee deaths because prosecutors said they lack evidence. He will face charges in the Ohio slaying later.

Dahmer’s father and stepmother were in the courtroom Tuesday. His stepmother took notes during Ms. Becker’s testimony.