The lead NYPD detective in the Etan Patz murder case admitted in testimony Monday that defendant Pedro Hernandez told cops he dumped a box with the boy's body in a location that was actually a bakery in 1979 when the 6-year-old vanished.

Det. David Ramirez made the admission during cross-examination after prosecutors played a 2012 video in which Hernandez, who had just confessed, walked police through SoHo and pointed to a gated alley under 113 Thompson St. as the place he left the body.

"Would it be fair to say that in 1979 the door at 113 Thompson opened directly into a bakery?" asked defense lawyer Harvey Fishbein.

"Yes," responded Ramirez.

Hernandez, 54, a married father from Maple Shade, New Jersey, is accused of abducting and strangling Etan as the boy was on his way to catch a school bus in SoHo on May 25, 1979. Hernandez at the time was working at a bodega in the neighborhood. In 2012 confessions -- the key prosecution evidence -- Hernandez said he lured Etan into the grocery's basement by offering the boy soda, killed him, put the body in a bag and a box, lugged it a block and a half away, and left it.

The defense contends the confession was something Hernandez imagined, the product of a mental disorder and police pressure during a seven-hour interrogation. Prosecutors say he privately had described killing a boy to friends years earlier. The issue of where he put the body is the latest of several glitches to emerge at trial over the accuracy -- and genuineness -- of his confession. He incorrectly described a book bag the boy was carrying, got the weather wrong and didn't remember an airline pilot's cap Etan was wearing when he left home the day he disappeared.

Hernandez admitted killing Etan after seven hours of questioning by the NYPD in New Jersey on May 23, 2012. He was then videotaped describing how he strangled Etan and claiming he was alive and moving when he put him into a box.

Jurors Monday saw him say he didn't know why he did it -- "It was just something that happened." They saw him sign an Etan missing poster with the words, dictated by police, "This is Etan Patz. I choked him."

After the session -- in which Hernandez sobbed and was praised by police for showing the "strength of the Lord" -- he was transported to Manhattan, Ramirez testified, and showed his route from the bodega to the Thompson Street site. If he picked a spot that was a bakery in 1979, Fishbein said, it could be because he made it up.

"He takes them to a place that's wrong and he does it in a very confident way," Fishbein said outside court. "What Mr. Hernandez says and does is unreliable."