MARTINEZ — A parade of defense witnesses spent most of Thursday painting a glowing picture of Concord elementary school teacher Joseph Martin until the final student, a high school girl who had the teacher in 4th grade, dropped a bombshell.

As defense attorney Patrick Clancy placed his hand down a boy mannequin’s T-shirt and rubbed its chest, as he did with most of his former student witnesses in the molestation trial, he asked the girl if she ever saw Martin rub any student’s nipples.

“Yes,” the 9th grade student said to a stunned Martinez courtroom. Clancy repeatedly tried to clarify if the touching was under or over the shirt, but the girl kept saying it happened under the shirt.

The girl later told prosecutor Derek Butts she saw Martin massage the nipples of one of the victims identified as John Doe while the boy sat between his legs during circle time.

The revelation came in the third week of the molestation trial, on the day the defense called its first witnesses. The girl’s testimony sparked an animated exchange between Butts and the defense attorney’s investigator who had interviewed the girl numerous times before her court appearance.

Martin, 46, of Martinez, has pleaded not guilty to 150 molestation counts involving 14 former male students at Woodside Elementary School in Concord.

Most of Thursday’s testimony consisted of former students, parents, colleagues and friends of Martin — all female — saying how great he was as a teacher and how much fun he made learning.

The former students said they saw nothing inappropriate in class. Clancy repeatedly asked about agossip mill among students talking about Martin’s 2013 arrest and online comments from a local blog. The defense attorney contends the accusers were caught up in “group hysteria” that led to false accusations.

One girl who had Martin as her 5th grade teacher until he was placed on leave in 2013, also initially said she saw Martin put his hand beneath a student’s shirt and rub his nipples. However, Clancy and Butts asked for clarification on what she saw and she changed her response to reflect that she saw Martin touching boys over their clothing.

The second girl, however, refused to back off her testimony that she saw under the shirt touching, even when Clancy asked if she had just told his own investigator in the hallway that there was no inappropriate touching.

After the girl was excused, Clancy immediately called private investigator Carol Palacio to the stand and she testified that when she asked the girl if she saw any inappropriate touching she had said no.

Butts asked why she did not ask the girl and other defense witnesses specifically if they saw Martin touch any children under their shirts. Palacio said she felt her question of “inappropriate touching” covered that.

In the heated exchange, Butts asked her: “Do you think a 5th grader understands what’s inappropriate?”

Palacio said the girl’s testimony was a “surprise” to her.

The case continues Monday.

Contact Matthias Gafni at 925-952-5026. Follow him at Twitter.com/mgafni.