Editor's note: Kelly Wallace is CNN's digital correspondent and editor-at-large covering family, career and life. She is a mom of two. Read her other columns and follow her reports at CNN Parents and on Twitter.
(CNN) -- It is a case about alleged bullying that garnered national and international attention.
Before she jumped to her death in September,12-year-old Rebecca Sedwick of Lakeland, Florida, was repeatedly bullied on- and offline, Polk County Sheriff Grady Judd said at the time.
About a month later, Judd announced that two teens, 12-year-old Katelyn Roman and 14-year-old Guadalupe Shaw, were charged with aggravated stalking and accused of being Sedwick's chief tormentors.
But then, just a month after the arrests, the charges were dropped, with attorneys for the accused citing "zero evidence" of stalking in the case. (CNN does not typically identify minors who are charged as juveniles, but the network is doing so in this case because their identities have been publicized by law enforcement and have received broad publicity in local media.)
Now, as the extensive police file surrounding the case has become public, there are new questions about what evidence existed to back up claims that Roman and Shaw cyberbullied Sedwick and that their bullying, on- and offline, continued right up until her suicide, as alleged by the Polk County sheriff.
'Abysmal lack of any evidence'
"I don't think I was prepared for the abysmal lack ... of any evidence of bullying for the seven months prior to her suicide," said Nancy Willard, director of Embrace Civility in the Digital Age, a group that focuses on combating cyberbullying, and author of a handful of books including "Positive Relations @ School (& Elsewhere)."
Willard, who has no direct affiliation with the case, obtained the police files and reviewed them. She points to the Sedwick case as yet another example of law enforcement and the media being quick to make a judgment that bullying caused a suicide when other factors might have been at work.
"The research ... clearly indicates that when bullying is implicated in a suicide, there are other factors involved," Willard said, referring to research on bullying in general. "Are we going to, at this point in time, any time a child suicides, find another kid to blame?"
Judd's office says it stands by the arrests and the investigation. The police documents "support the probable cause that our detectives found during their investigation -- probable cause that clearly supported the charges of aggravated stalking," said Donna Wood, a public information officer for the Polk County Sheriff's Office.
"We never said that bullying was the only reason Rebecca committed suicide," Judd told The Associated Press. "But what the bullies did is that they continued to stack bricks on an already overloaded wagon till finally, it broke."
Inside the police file
More than a year before her death, Sedwick had been battling depression resulting from her deteriorating relationship with her father, according to intake reports from a counselor that are included in the police file. She also complained about fights between her mother and stepfather. The file, which has been reviewed by CNN, says she cut herself on a few occasions, had suicidal ideations and had been committed for psychiatric evaluation for two days.
In November 2012, she accused her mother of abusing her and then took back the accusation, saying she was pushed to lie by classmates who forced her off campus and told her they wouldn't let her return home unless she lied to an officer. Her mother denied abusing Sedwick but said she slapped the girl's face once during an argument about Sedwick being too young to date.
Sometime before her death, Sedwick's relationship with an online boyfriend came to an end, according to the documents. Family conflict, in addition to bullying from girls at school, weighed on her.
In her notes, Sedwick wrote about suicide and in the weeks before her death she did Web searches on how many sleeping pills or Advil it would take to die.
Mother: Bullying was the cause
As a more complicated picture of Sedwick emerged in media reports about the police file last week, Tricia Norman, Sedwick's mother, said people were looking for other sources to blame. Norman told The Ledger, a local newspaper in Lakeland, that she remains convinced bullying was the reason her daughter decided to end her life.
"I really don't think there was any other factors involved," said Norman, who accused people of trying to dig into her personal life. She added: "What Rebecca was upset over in her life was these girls not leaving her alone."
Norman alleged in a recent interview with CNN that once Sedwick's suicide and the bullying allegations began making headlines, the girl's Ask.fm social networking page was deleted from the site. Any evidence of bullying may have been wiped away, she said.
"I most certainly want to know what happened. ... I know she was bullied, I know it was horrific, but that morning is what pushed her over the edge," Norman said.
Norman and Judd are on a mission to ensure that companies behind "disappearing apps" that can be used for bullying keep records of data that passes through the sites and provide it to law enforcement when appropriate.
Ask.fm said it cooperates willingly with authorities and recently added a "safety" page to its website, saying bullies are not tolerated. The company said in a statement: "From our experience we have seen that reports of suicide cases often tend to present premature and simplified conclusions about tragic events, which are always a complex overlap of different factors."
Norman's attorney, David Henry, said last week that he has evidence to prove that Sedwick was repeatedly bullied until her suicide and that the bullying was a cause of her death.
"Our position is that the bullying did continue under a few different forms, but had the school stepped in and stopped these girls early on, then it would not have continued, and it would not have built up," said Henry, who would not comment on specific evidence proving the ongoing bullying.
Henry said he plans to go forward with a lawsuit against the Polk County School Board and one or both of the girls who were arrested in the case.
"As of right now, on our end, we haven't received the lawsuit, and we wouldn't comment until that actually does happen," a Polk County School Board representative said. The girls' attorneys could not be reached for comment.
Teens admit some 'bullying'
What's not in question is that Sedwick had issues and run-ins with Roman, Shaw and possibly others from December 2012 through February 2013, seven months prior to her suicide.
In an interview with investigators, Roman confessed that she "bullied" Sedwick during the sixth grade at Crystal Lake Middle School, calling her names such as "ugly" and saying she was a "ho." Shortly after a fight in February 2013, she admitted sending Sedwick a message saying something like, "No one will miss you if you die." During the police interview, she also said that she was "sorry" for bullying Sedwick.
Shaw, who went on to date Sedwick's ex-boyfriend shortly after they broke up, admitted under questioning to sending a Facebook message to Sedwick stating "Nobody likes you" and said that she used to "bully" Sedwick but that it had been a long time.
Other students remembered it. A student who said Shaw bullied her in elementary school said she witnessed Shaw tell Sedwick that she "should go kill herself' and that she "should die" on numerous occasions during the school year.
Another student told investigators she observed Shaw bullying Sedwick on a daily basis between December 2012 and January 2013 and recalled a specific incident in which Shaw told Sedwick to "drink bleach and die."
Norman, Sedwick's mother, said the bullying got so bad that she took her daughter out of Crystal Lake Middle School in February 2013, home-schooled her for the remainder of the school year and enrolled her in a new school in September. At the time of Sedwick's death, Norman said, she had only recently learned that the bullying from former Crystal Lake classmates had continued via social media and text applications.
Little evidence of cyberbullying
The police file does not contain extensive evidence that the bullying continued until Sedwick's death. There is also little evidence to support Judd's claim that Shaw and Roman repeatedly bullied her online.
In one text exchange with an unidentified friend, Roman says she bullied Sedwick in person and online, according to the police documents. When her friend asked, "So your telling me for the past few weeks you've been bullying her online?" Roman responds, "Yea im bully i deserve to die it was me and not her."
The piece of cyberevidence, which Judd said led to the arrest of Shaw and Roman, was a Facebook post on Shaw's page on October 12th of last year, which said, "Yes ... I bullied REBECCA nd she killed her self but IDGAF," the ending short for "I don't give a f***." But Shaw's parents said that she was asleep at the time of that posting and that her account had to have been hacked.
Sedwick's family captured screen shots of anonymous messages on various text message apps telling Sedwick to "kill" herself and to "just die," but those messages were ultimately deleted.
Judd's office said it attempted to obtain records from companies that run anonymous social media apps, and the requests "were in process" at the time the state attorney "resolved the charges" with Shaw and Roman, said Wood, the sheriff's spokeswoman. "Because the case was closed at that time, we ended our attempt to obtain the records from those companies."
Although no one can yet say who sent those anonymous messages, it is clear that Rebecca Sedwick was a girl in turmoil.
In the police file, there are handwritten notes from Sedwick, including one in which she listed "bad things" people called her such as "ugly, "slut" and "outcast" and "good things" she got called including "pretty," "nice" and "beautiful." At the bottom of the page was the word "suicidal."
Another one of her notes began, "There is a war in my mind," according to the police file.
"She was fighting with herself over whether to commit suicide," said Willard, who wrote her first book about cyberbullying in 2007.
Willard hopes the Sedwick case raises awareness not just on how bullying "is never the whole cause" of suicide but on how the whole theory that bullying causes suicide can end up endangering children who are suffering. For instance, she points to a case in Illinois where a student who was bullied killed himself the day after watching a movie in school about bullying.
"There's absolutely zero evidence that that's going to stop kids from bullying, but there's major concern that it's going to give kids who are being bullied the idea that that's something they should consider."