PORTLAND — When Falmouth police Officer Robert Ryder entered the yard behind Paula and Barry Spencer’s home around midnight June 16, the dozens of teenagers there reacted almost instantly.

“Kids just scattered,” said Ryder, a 25-year police veteran. “I saw alcohol containers being dropped, kids getting out of the pool, running into the woods or into the house.”

Empty beer cans, wine bottles and wine coolers littered the patio, swimming pool and hot tub areas, he said. A grape-vodka bottle sat on a picnic table.

Ryder’s testimony Tuesday in Cumberland County Unified Criminal Court was the first glimpse provided by police of the party that led authorities to charge each of the Spencers with nine counts of allowing minors to possess or consume alcohol.

In the second day of the Spencers’ trial, Ryder and five teenage witnesses provided new details about the party, how teenagers learned about it and what the two parents did to prevent drinking on their property.

The Spencers hosted the party after their son’s baseball team won the state high school Class B championship. The party got out of control after Falmouth High School’s championship lacrosse team joined in.

Ryder testified that when Paula Spencer identified herself, he confronted her about the minors drinking and the empty bottles and cans strewn around the patio.

“She said, ‘They’re all mine,’ ” Ryder recalled. “I said, ‘That’s not going to cut it.’ “

Ryder testified that he smelled alcohol on her breath.

A witness for the defense testified Tuesday that the Spencers took pains to find and dispose of the alcoholic beverages.

Connor Burfiend, a 2011 graduate of Falmouth High School who’s now 19, said he watched both adults use flashlights to check bags for booze between about 10:30 and 11 p.m., when he walked from the house to his car to get a cellphone.

Because of the searches, students began coming through the woods in the rear of the home, “I assume to try to sneak in alcohol,” Burfiend said.

The trial will continue Wednesday morning. The Spencers could face thousands of dollars in fines and as much as a year in jail if convicted.

The young witnesses, who ranged from 15 to 19 years old, gave differing accounts of how Paula and Barry Spencer responded to the drinking. Their testimony also depicted a gathering that, by most accounts, spiraled out of control.

Among those who got in somewhat surreptitiously was John Cooper Lycan, who was 17.

He said he cracked open his first beer that night during the car ride his sister gave him to the Spencers’ house on Field Stone Drive around 8 p.m. — one of 30 cans that a friend hid in a backpack.

Lycan and a few friends entered the side of the property, he testified, and the Spencers never told him he couldn’t drink. He said he concealed his drinking by pouring the beverages into cups and tossing empty cans into the woods nearby.

“As the night went on, (drinking) was less and less concealed,” said Lycan, who’s now 18 and a senior at Falmouth High.

When the party grew, later in the evening, Lycan said, he saw Barry Spencer confiscate two beers from a student.

Lycan, who was later found by police passed out drunk on a nearby lawn, testified in exchange for a guarantee of immunity from prosecution.

Alexander Cattell, who’s now 18 and a student at the University of Connecticut, said that when he arrived around 10:30 p.m., he saw a group of students he didn’t recognize approach the home. He said Barry Spencer warned the other groups from his position on the driveway.

“He said, ‘If you have any alcohol, please get rid of it or don’t bring it in,’ ” Cattell said.

Once he was inside the home, Cattell realized that others were drinking and retrieved a plastic bottle half-full of rum from his car.

“I broke his code,” Cattell said, referring to Barry Spencer’s warning against illegal drinking. Cattell said he drank “because everyone else was doing it.”

When police arrived around midnight, Cattell watched from around a fire pit as a few dozen others fled into the woods, he said.

A 17-year-old senior at Falmouth High School, whose name is being withheld because of her age, said she was one of the students who ran into the stand of trees. While she stood on the edge of the wooded area waiting for her parents to pick her up, she said, a police officer tackled her, bruising her hip.

The girl said she saw Barry Spencer in the driveway of his home around 10:30 p.m., when she arrived, and he told her not to drink.

Her recollection of whether Spencer was checking bags was hazy, and she could not provide a clear answer as to whether she saw him check for booze.

The youngest to testify, a 15-year-old student from Portland, said she got a text message about the party and arrived around 11:30 p.m., only to be found by police a half-hour later.

When asked by Cumberland County District Attorney Stephanie Anderson why she was summonsed, the teenager did not mince words: “I was intoxicated.”