The curator testified that animals had been euthanized in shocking ways at the Reston Zoo: Some were shot, rabbits were slammed into walls and chickens were fed to pythons.

But in a Fairfax County courtroom Friday, Ashley Rood said she reached her breaking point after uncovering evidence that the zoo’s director, Meghan Mogensen, had drowned an injured wallaby named Parmesan in a plastic bucket.

Rood confronted Mogensen, resigned in protest and later called police.

“I think you and your father are sick and sadistic people, and I don’t want to be part of this anymore,” Rood recalled telling Mogensen, whose father owns the zoo. “It’s one thing to euthanize an animal, but it’s another thing to drown it.”

Mogensen, 26, of Silver Spring, was convicted of animal cruelty and sentenced to 30 days in jail after Rood’s whistleblower complaint. A judge also found her guilty of possessing animal anesthesia without a license.

Meghan Mogensen (Fairfax County Police)

The unusual trial featured testimony about a wallaby autopsy known as a necropsy, veterinary forensics experts and fingerprint analysis as prosecutors sought to show that Mogensen cruelly killed the wallaby and then mounted an elaborate coverup.

The testimony also raised questions about the zoo’s care of its animals. Other zoos owned by Eric Mogensen have also come under scrutiny in recent years, according to media reports.

Meghan Mogensen’s attorney, Caleb Kershner, contended that his client, who didn’t testify during the trial, had humanely euthanized the wallaby using a lethal injection and was acting out of compassion for an animal in pain.

“She was concerned about this animal,” Kershner said in his closing statement. “It was suffering.”

Rood testified that Parmesan had injured its left eye while hopping about its pen at the end of January. Rood said zookeepers bandaged the wallaby’s eye and put the animal in a plastic crate but that Parmesan managed to bang its head again and punctured the eye, which started bleeding.

Rood said she then told Mogensen the animal was injured and that Mogensen consulted with her father about what to do. Eric Mogensen wanted to euthanize the wallaby, Rood testified, a decision that left her “dumbfounded” since she thought the animal could be treated by a veterinarian.

Rood said Mogensen ordered her to pick up food for the animals, but when she returned to the zoo she found Parmesan’s open crate next to a spigot and a bucket that had water in it. Rood said she suspected Parmesan had been drowned.

She testified that she jumped into a Dumpster and ripped open a trash bag, which contained the “soaking wet” wallaby. Rood said she was furious and immediately confronted the younger Mogen­sen.

Rood recalled the zoo director telling her: “These animals are Eric’s property, and we need to do what he wants with them.”

Fairfax County animal control officer Jennifer Milburn testified that Mogensen indicated to her that she had humanely euthanized Parmesan by injecting the animal in the neck with a euthanasia drug.

But Milburn and the examiner who performed the necropsy found no sign of a needle stick. The necropsy also found no sign of the euthanasia drug in the wallaby’s system and found blood in the animal’s lungs, which the examiner testified is consistent with drowning.

When officers searched Mogensen’s office, they found ketamine, an animal anesthetic, in Mogensen’s safe. According to testimony, she did not have the proper Drug Enforcement Administration license to possess the drug.

Officers also uncovered two versions of a euthanasia report on Mogensen’s computer and in her files. One said Parmesan had been drowned in a bucket, while the other was altered to say the wallaby had been “humanely euthanized.” The latter version was later sent to Fairfax County police by the zoo.

One of Mogensen’s fingerprints was also found on a hard copy of one of the reports, which was in her files, according to testimony.

Detectives who scoured her computer discovered she had searched on Google for whether drowning an animal constitutes cruelty in Virginia.

“We have her lying, lying and lying again,” said Michelle Welch, an assistant state attorney general, who specializes in animal cases and led the prosecution.

Kershner said Mogensen will appeal the conviction. And Rood, who has been searching for work since she resigned from the zoo, said outside court that the outcome justified her decision to come forward.

“It made everything I did worth it,” she said.