A vast majority of sexual assault cases never result in police complaints and fewer still are prosecuted in court.

So the fact that prosecutors are seeking charges against three men and a 17-year-old in the rape of 19-year-old LSU student Madison Brooks suggests that investigators probably built an unusually strong case against them, an attorney and advocate for sexual assault survivors says.

Survivors face huge challenges — questioning of their motives, among others, and inaction by authorities — in reporting an assault and participating in an investigation, Morgan Lamandre, director of local outreach group STAR, said at the Baton Rouge Press Club meeting Monday.

Even then, arrests are rare.

"So when people say 'she's not here to report that,'" Lamandre said, referring to Brooks, "there must, in my mind, be pretty significant evidence for that investigation to result the way it did."

Brooks had been drinking at popular Tigerland hangout Reggie's one night in mid-January before she left the bar with the 17-year-old and three men, sheriff’s deputies wrote in an affidavit. The arrest documents say the group pulled over after leaving the bar and the 17-year-old, who has not been identified because of his age, and 18-year-old Kaivon Washington took turns raping her in the back of the car.

Attorneys for the men and the 17-year-old have described the acts as consensual and say they have video evidence that proves it, though they have not released the footage.

Later, Brooks could not say where she lived and the four males dropped her off in a subdivision, arrest documents say. She was struck by a vehicle on Burbank Drive around 2:50 a.m.

The case has since drawn national and international headlines and roiled LSU's campus. Students criticized the administration's handling of Brooks' rape and death, saying it highlighted years-long patterns of inaction by university officials.

Yet the case has drawn more of a response from the criminal justice system than most sexual assaults, according to data from the organization RAINN, a national group that advocates against sexual violence and runs a hotline for survivors. Of every 1,000 sexual assaults, only 50 yield arrests, according to data compiled by the organization.

Lamandre — whose organization, Sexual Trauma Awareness and Response, offers court representation and other resources to sexual assault survivors across 15 Louisiana parishes — added that even cases where a survivor submits a complaint don't often yield prosecutions.

So "there must have been something pretty significant for there to be a decision to charge individuals when there was no reporting by a victim," she said.

Physical evidence in the case includes Brooks' blood alcohol content, which first responders obtained before she died from injuries in the crash and found to be .319 — nearly four times the legal limit to drive a vehicle, arrest records say. The documents also say her autopsy revealed signs that she had been raped.

Defense attorneys have attacked that evidence, claiming at a press conference that the BAC figure is flawed and that video shows Brooks acting more coherently than a person inebriated at that level.

Lamandre emphasized that each sexual assault case is different and that survivors should be able to choose whether to file complaints.

Still, the Brooks case offers a model for how the system can handle such cases insofar as it shows how investigators can work to build probable cause in sexual assault cases, she said.

"As it relates to there being what truly looks like a deep-dive into finding facts, finding enough evidence to make an arrest, I think that is a model, and we should commend law enforcement for doing their due diligence to get whatever they needed to find enough probable cause to arrest those individuals," Lamandre said.

Editor's note: This story has been updated to more accurately reflect when Madison Brooks died.

James Finn is a criminal justice reporter based in Baton Rouge for The Advocate | The Times-Picayune. Email him at jfinn@theadvocate.com or follow him on Twitter @rjamesfinn.