NEW YORK -- After four teens allegedly involved in the gang rape of an 18-year-old woman in a Brooklyn playground were arraigned Tuesday night, one of their lawyers began speaking out about a video he says calls the prosecution's version of events into question.

According to complaints filed in the case, five teens in all were involved in allegedly forcing their 18-year-old victim to have oral, anal and vaginal sex before police found her alone in the playground where she was attacked, with bruises and cuts. Pieces of her clothing were found strewn near the park. She was hospitalized and interviewed the next day.

The suspects have been identified as Denzel Murray, 14, Shaquell Cooper, 15, Ethan Phillip, also 15, Onandi Brown, 17. A fifth teen suspect, who has been identified as Travis Beckford, 17, was arrested after being found at school after a search, authorities said, and is expected to be arraigned by Wednesday night.

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Brooklyn Assistant District Attorney Lisa Nugent said in court that none of the four suspects arraigned Tuesday was identified by witnesses who viewed lineups and photo arrays. After their capture, at least two told investigators they believed the sex was consensual, police said. The four teens who appeared on Tuesday face rape, criminal sex act, sexual abuse and other charges and each denied the allegations through their attorneys.

After he was retained on Tuesday to represent 14-year-old suspect Denzel Murray, Attorney Kenneth Montgomery spoke publicly about the existence of a video he says shows part of the incident.

Montgomery said he saw a roughly 12- to -15-second clip that did not appear to represent the entirety of the incident, but in which he believes the victim's facial expressions suggest a different story than the one being presented by prosecutors.

"She seemed to appear to be grinning and smiling," Montgomery tells 48 Hours' Crimesider. "There was some conversation that seemed to be taking place and she seemed to be on the ground by herself" responding non-verbally to male voices off-camera, he said.

When pressed as to whether the alleged victim might have been expressing distress, Montgomery said, "I wouldn't consider it a grimace."

He also said that as far as he could tell, his client had not been accused of anything apart from being present during the commission of the alleged crimes.

He would not say where he got the video or who took it, citing attorney/client privilege. Montgomery said his client turned himself in with his mother, has no criminal record and attends one of the best high schools in New York City.

"They never made an assertion that my client, which is the one I'm concerned about, even participated in a sexual act," said Montgomery, who has handled other high-profile cases, including representing the plaintiff in the rape case against civil rights lawyer Sanford Rubenstein.

Police Chief of Detectives Robert Boyce said the alleged victim in the Brooklyn playground case gave a very credible report. "She had physical injuries at the time," he said. "She was traumatized."

The father said he wandered around for several minutes in a futile attempt to get help, according to authorities. He said he went into a store but a merchant refused to let him use a telephone, they said. He then flagged down two police officers and told them his daughter was maybe being murdered, Boyce said.

"Apparently he was hysterical," Boyce said. "He said a gun was pointed at him."

However, Montgomery said that so far unverified reports that have surfaced, alleging that the victim's father may have been engaged in sex acts with his daughter prior to the attack, could call his statements as a witness into question.

"If he is someone that is looked at for wrongdoing, any statements he makes as to what happened should be looked at very closely," Montgomery said.

Authorities said they were told the attack began Thursday night after the 18-year-old woman and her 39-year-old father decided to drink beer together near a handball court at a Brooklyn playground that residents say usually is quiet and empty at night. The two were drunk, officials said. The woman told investigators that a group of teenagers approached them in the park and ordered the father to leave. When he returned moments later and hurled a bottle at the teens, one teen pulled out a handgun and chased him away, according to investigators. While he was gone, they allegedly gang raped her.

"I have a suspicion, based on what I've learned so far, that that isn't an accurate representation of what happened," Montgomery said.