Natalie VanderNoot, left, of Lebanon, N.H., and Sophia Miller, of Grantham, N.H., compete for Lebanon High School in a forensics event on Saturday, Dec. 16, 2017, during the Northern New England Science Olympiad Invitational Tournament at Dartmouth College's Life Science Center in Hanover, N.H. In the forensics event the students were challenged with solving a crime. (Valley News - Charles Hatcher) Copyright Valley News. May not be reprinted or used online without permission. Send requests to permission@vnews.com.
Natalie VanderNoot, left, of Lebanon, N.H., and Sophia Miller, of Grantham, N.H., compete for Lebanon High School in a forensics event on Saturday, Dec. 16, 2017, during the Northern New England Science Olympiad Invitational Tournament at Dartmouth College's Life Science Center in Hanover, N.H. In the forensics event the students were challenged with solving a crime. (Valley News - Charles Hatcher) Copyright Valley News. May not be reprinted or used online without permission. Send requests to permission@vnews.com.

Hanover — The four teenage girls had been asked to solve a crime.

And so there they were, black smocks and safety goggles pulled over their sneakers and ponytails as they analyzed the evidence before them — a bit of fiber, a partial fingerprint, a few drops of blood, and a shred of plastic from the card used to pick the lock, all left behind by the criminal.

The first step was to identify six different mysterious white powders that sat in neatly labeled containers on the lab table, which was also littered with tape, scissors, a water bottle and small stoppered vials of chemicals.

“Lumpy or crystalline?” one of the girls muttered, squinting intently as she dragged a toothpick through one of the powders. Was it glucose?

She eventually determined it was sodium bicarbonate — one of the main ingredients of baking soda.

It may sound like the latest spinoff from the Scooby Doo universe, but the girls — seniors Natalie VanderNoot, Sophia Miller and Faith Powell, and sophomore Madeline Wolfe — were representing Lebanon High School at the Northern New England Science Olympiad.

“Knowing how things work is really reassuring to me in a way,” VanderNoot said. “To know that this is what’s happening on a molecular level and to know why something is moving in a certain way. I like to know how things work.”

Outside their laboratory, throngs of students from 20 teams milled around in the halls of the Life Sciences Building at Dartmouth College, competing in other events that ranged from building the strongest tower, to demonstrating the best mastery of astronomy.

VanderNoot and Miller made up one team, while Powell and Wolfe comprised another; though the mood was often intense, each pair had companionable workflows.

When Wolfe tried to blot up some spilled water with the exam papers, she and Powell briefly devolved into a fit of tension-relieving giggles. They had 50 minutes to assemble the strongest forensic evidence against one of a handful of suspects — was it Samuel, the professor? Or Jessica, the lab manager?

Or perhaps it had been one of the students — Misty, James, Satoshi or Brock, each of whom was described by a set of “constable notes” that identified the suspect’s blood type and materials worn.

Working through these types of problems is the fundamental skill in STEM (science, technology, engineering and math) fields, and in New Hampshire, not enough girls are tackling them.

Ten years of data from an annual survey of high school graduates (compiled by The Alliance for Science & Technology Research in America) contains a bit of good news, and a bit of bad news — since 2008, the percent of New Hampshire female graduates that indicated a desire to work in a STEM career increased, from 14.8 percent, to 18.1 percent, outpacing the national average of 16 percent.

The bad news for gender parity is that boys’ interest in STEM fields is increasing too, at a much quicker rate than girls.

Since 2008, the number of male New Hampshire high school graduates interested in a STEM career increased from 35.5 percent in 2008 to 45.8 percent in 2017, which means the state’s girls are actually losing ground.

That disparity can be self-perpetuating, in ways large and small. Miller said that, a couple of years ago, she and an all-female team of lab partners had been derided by a couple of boys during a chemistry class.

“ ‘Girls can’t do science,’ ” they told her. She said she couldn’t tell if they were in earnest, or trying to make a bad joke.

“I’m like, ‘OK, but I’m doing the lab and you’re not,’ ” she said.

When fewer girls are able to maintain an active and healthy interest in science, fewer women enter those fields, which often command superior salaries and account for much of the pay gap between men and women in the workforce. The Institute for Women’s Policy Research found that, in New Hampshire in 2015, just 24.6 of people working in STEM fields were women, lagging a similarly problematic national average of 28.8 percent.

Back in the lab, the two teams of girls were using the same information, but getting different results.

Wolfe and Powell were zeroing in on Jessica, the lab manager, as the culprit, based largely on the evidence of the fingerprint, while Miller and VanderNoot were building a case against James, one of the student suspects.

“We had a blood-typing kit,” VanderNoot said, after the competition had ended. “There were different antibodies you can use to figure out whether it was A positive. … The blood type was B positive. And there were only two suspects who had B positive blood. James was one of them. And Samuel (the professor) was the other.”

The Science Olympiad is one of the few STEM programs that’s achieved gender equality — the group has partnered with the Million Women Mentors organization, and boasts a roughly equal number of girl and boy participants on 7,600 teams nationwide.

John Tietjen, the Lebanon High Science teacher who got the local Science Olympiad rolling in 2015, said some classrooms and science subject might tell a different story than others.

“I’m a chemistry teacher. In chemistry, I don’t see any sort of gender bias there. It’s right down the middle,” he said.

But some of the engineering classes, he said, still seemed to draw a disproportionate number of boys.

For VanderNoot, a summer program with Johns Hopkins University was the catalyst for an interest in biomedical science — “that was it,” she said. “I decided I was really interested in how the body works, and diseases. I’ve been studying any variations of biology that I could find since then.”

VanderNoot bypassed seventh grade and has now, at 16, been accepted to three colleges, including one of her top choices, George Mason University in Virginia.

About three quarters of the way through the forensics competition, VanderNoot and Miller engaged in an urgent, whispered consultation. The fingerprint was proving to be a problem for their main suspect, James.

“There were too many things about the fingerprint,” VanderNoot said. “That was a big part of the test, was identifying loops, whorls and arcs, which are the three main types, and then little things you can look for. He just had the wrong classification.”

They began hurriedly reviewing their work, and quickly realized that they might have made an error in the blood test. A separate chromatagraph test had also gone awry, leaving them with only a partial answer.

They pored over the evidence with fresh eyes, and with only minutes left to go, abruptly erased James from the answer sheet, filling in Jessica’s name instead.

“When we looked back at the evidence, Jessica’s profile fit better, from the powder test,” VanderNoot said.

When the results were announced later that day by Dartmouth chemistry professor and graduate school dean Jon Kull, it turned out that Jessica had indeed been the criminal, and VanderNoot and her friends had proven their forensic skills in spades, taking first and second place from a field of 17 teams in the event. That result was much better than the teams as a whole fared — Lebanon took 11th and 12th place overall, while top honors went to Plattsburgh High School, from New York.

Dartmouth, according to Kull, graduates a higher rate of females in engineering than any other school in the country.

“We know there are serious barriers to participation in STEM, which become tougher for women to overcome beyond high school, and tougher for others who are asked to find a job rather than pursue academia,” he said. “When we don’t effectively remove barriers to participation, we are narrowing the path of discovery. … Dartmouth works to remove these barriers and to break down those stereotypes, and as we take on the mantle of hosting the Science Olympiad in the future, we look forward to reducing those barriers even further.”

Matt Hongoltz-Hetling can be reached at mhonghet@vnews.com or 603-727-3211.