In one snippet of video, Heather Lewis asks for a response from the bound and blindfolded girl on whom she is performing a sex act. There is no response. The girl is motionless.

"Can I get a yes, a no, something?" says Lewis, who is accused of sexually assaulting the girl — who authorities say was a juvenile when the assaults happened — and two other juvenile girls with her former boyfriend, Robert Melia Jr., a Moorestown police officer. The abuse happened over eight years in Melia's home, and one encounter was videotaped, authorities said. He was arrested in April 2008 and suspended from the force.

In another clip, a muscular-looking hand that the prosecution suggested was Melia's comes into the camera's view as Lewis is heard repeating commands to remove the bed covers on the girl.

The two videos were among 20 such clips — each from 10 seconds to about two minutes long — shown to the jury Wednesday by Assistant Burlington County Prosecutor Kevin Morgan. In one, Lewis is giggling; in some others, she is seen inserting sex devices into the girl — and imploring her to respond. The victim, Morgan said, was "a rag doll."

The video, a critical piece of the prosecution's evidence, proves that Lewis forced the girl to have sex and that Melia videotaped the acts and tried to keep his involvement discreet, Morgan said. He said Melia kept his face hidden because, as a police officer, he knew the consequences of forcing the girl into a sex act.

"This was not some fantasy. This was not role-playing. This was outright depravity," Morgan told the jury during his closing arguments in Superior Court in Mount Holly, rebutting defense arguments that the sex was consensual and that the girl was an adult when it happened.

The jury of eight men and four women began deliberating after Morgan concluded his closing statements in the nearly three-week-old trial. Attorneys for Melia and Lewis gave their closing statements Tuesday, arguing that the accusers had lied and that prosecutors were overzealous, in part because of the case's notoriety and the alleged involvement of a Moorestown officer.

"A witch hunt" is how Lewis' public defender, Bonnie Geller-Norman, summed up the case.

Lewis, 36, and Melia, 42, face more than 40 counts each of aggravated sexual assault, sexual contact, endangering the welfare of a minor, invasion of privacy, and other charges. Each could face more than 52 years in prison, prosecutors said.

Police have said that, during a search of Melia's Cottage Avenue home, they also discovered video of Melia engaged in sexual acts with calves on a Burlington County farm. A judge dismissed the counts in 2009, saying there was no evidence the animals had been tormented by the acts.

Lewis also faces charges of allegedly sexually assaulting a boy, 14, and forcing him to have sex. It was the boy's first time having sex, Morgan said.

"Probably not anyone's idea of a romantic first time," Morgan said.

On Tuesday, Lewis testified that the alleged abuse never happened and that she never forced anyone, including minors, to have sex.

The girls, two of whom are sisters, said they were between 12 and 17 when they were assaulted separately by Melia and Lewis. They told police that Melia and Lewis used vibrators on them and forced them to engage in other sex acts with them. The girls had difficulty pinning down exact dates or how old they were when they were abused.

The entire 35 minutes of video, taken in August 2005, was shown to the jury last week. It was extracted from Melia's computer, authorities said.

Morgan said Wednesday that he wanted to spare jurors from having to watch the entire video again, because, when they saw it the first time, they "became angry."

Melia's attorney, Mark Catanzaro of Moorestown, has said there was no evidence that his client was there during the taping. Morgan said Melia was careful about being caught and had tried to destroy the video.

Lewis testified that the girl in the video was 18 and had consented to the sex acts. As for a male-sounding voice heard on the video, Lewis said, the encounter was videotaped by an "ex-girlfriend of mine" with a deep voice whom she described as "butch." She asserted that she was not trying to protect Melia, who has been a father figure to her son from a previous relationship and still visits him every week.

Morgan sought to counter those assertions. He said a man could be heard coughing and making another sound on the tape.

"Look at the mass of the arm," Morgan also said, referring to the person seen removing the covers. "It's a man's arm, it's not a large female."

Contact Darran Simon at 856-779-3829 or dsimon@phillynews.com, or follow on Twitter @darransimon.