Jurors in the Etan Patz murder trial on Tuesday got their first look at a videotaped confession to strangling the 6-year-old in 1979 given by defendant Pedro Hernandez to a prosecutor after his arrest in 2012.

"I grabbed him by the neck," Hernandez says in the video, describing the moments after he claims he lured Patz into the basement of a bodega by offering him a soda. ". . .I wanted to let go but I couldn't let go. I felt like something just took over me."

Patz disappeared on his way to catch a school bus in SoHo on May 25, 1979, and his body was never found. Hernandez, 53, of Maple Shade, N.J., who was an 18-year-old working in a neighborhood grocery at the time, is on trial in Manhattan Supreme Court.

He was questioned by police in 2012 based on a tip. He first confessed at the end of a lengthy NYPD interrogation, then showed police where he dumped the body in SoHo, and then gave a third videotaped statement. Prosecutors are showing the last confession first.

The defense contends Hernandez fantasized the crime due to mental problems -- he says during his confession that he has bipolar disorder. But witnesses have said he privately admitted killing someone three times, to a prayer group and his ex-wife and best friend.

The confessions were all shown at a pretrial hearing last fall. But jurors appeared rapt, intently taking notes and knitting their brows as they watched him describe the killing in a meek, singsong voice that had little affect or emotion.

According to testimony by members of the prayer group, he said in 1979 that he killed a boy after trying to abuse or sodomize him. In the confession, he gave no motive, and said he put the body in a box, dumped it in an alley, and immediately went back to work.

"I just feel like nothing," he told the prosecutor questioning him. "Nothing happened. Like I did nothing wrong. . . . I knew that I did something wrong, but it didn't bother me that much."

Some details of the confession could lend support to the defense theory that he made it up due to his mental problems.

For example, he said that Patz had a "bookbag" that was black, that he threw behind a refrigerator. But Patz's mother testified that her son was carrying a tote bag with a design of white elephants on a blue background.

Hernandez said that he carried the body a block and a half to an alley because there were no garbage cans in front of the bodega. But prosecutors have shown pictures of a large trash bin right next to the basement where the killing allegedly occurred.

Hernandez also said he returned to the alley the next day to see if the box was still there, but it was gone, and he continued working at the bodega. But prosecutors allege that he fled New York the day after the killing.