Almost six weeks after a Suffolk prosecutor told jurors that “wood chips” found on the bodies of two dead women were a link to the Manorville carpenter charged with their murders, jurors finally got a look Monday at that evidence.

There wasn’t a lot to look at, because the Suffolk County Police Department destroyed much of it years ago. And it wasn’t easy to discern, because when a millimeter-long particle is magnified enough to make it visible, it looks less like wood than it does straw.

Nonetheless, forensic scientist Clyde Wells of the Suffolk Crime Laboratory assured jurors that three of the seven particles that remain were wood. He couldn’t be sure what most of the rest were made of. One was a bit of glass or crystal and the others were unknown — possibly wood.

Wells testified before state Supreme Court Justice Richard Ambro in Riverhead at the second-degree murder trial of John Bittrolff, 50. He is accused of strangling and bludgeoning to death Rita Tangredi, 31, of East Patchogue on Nov. 2, 1993, and Colleen McNamee, 20, of Holbrook on Jan. 30, 1994.

Since Bittrolff’s arrest in 2014, Assistant District Attorney Robert Biancavilla has said more than 150 “wood chips” found on the bodies were evidence against Bittrolff because of his profession. He said they reflected his “signature style” of killing.

But none of the crime scene responders testified about seeing any woods chips on either body. And forensic scientist Thomas Zaveski testified earlier that the items — recovered from the victims’ clothing, rather than their naked bodies — were actually minute particles, visible only as specks.

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In the years since the killings, all the particles from McNamee’s crime scene were destroyed. Police have testified it was because of paperwork errors, but defense attorney William Keahon of Hauppauge has said it was deliberate, to protect a sergeant under investigation whose police car had wood shavings in it.

Biancavilla has also said Bittrolff’s DNA, left in semen recovered from both bodies, is the strongest evidence that he killed them both. Keahon has said the DNA isn’t evidence of murder.

Only seven particles survived from the Tangredi scene. Wells testified about those Monday.

He said a powerful microscope showed three of the specks to consist of yellow strands with tiny pits — the visual hallmarks of wood.

There was no way to tell what they were without magnification, he said.

“These are very hard to see with the naked eye,” he said.