In January 2012, Darren Sharper filed a worker's compensation claim in California that described several health problems he suffered during 14 seasons as a player in the NFL. Along with his knee, hamstring, shoulder and hip, he listed "head, sleep."
To help his sleep issues, the former NFL star had a prescription for Ambien, the brand-name version of zolpidem, a sedative used to treat insomnia. Sharper eventually became a frequent user, going through 70 pills in 65 days through mid-January of 2014, a prosecutor in Los Angeles said.
Investigators say he also slipped the drug into women's drinks, rendering them unconscious so he could rape them after a night of partying. On Jan. 17, Sharper had 20 Ambien pills in his possession when Los Angeles police arrested him on suspicion of two rapes there in October and January. Sharper since has been indicted for two more rapes in Arizona and is the subject of investigations in three other states, a stunning turn in the life of a well-known former player who had proudly touted his work at women's advocacy events and was working as an analyst for the NFL Network at the time of his arrest.
Sharper, 38, has pleaded not guilty and remains jailed, pending a hearing April 15. The case against him reveals a collision of two worlds, according to a USA TODAY Sports review of court records, police reports, workers compensation claims and interviews with independent experts and other former players. In one way Sharper is among a growing number of former football players who suffered head injuries on the field and later turned to zolpidem, sometimes to the point of addiction, to help with sleeplessness. Zolpidem is commonplace in the USA, ranking 15th on the list of most-dispensed medications in 2012 with 43.8 million prescriptions, according to IMS Health.
Police say it also is the drug Sharper used to prey on women, with zolpidem known as one of the most effective date-rape drugs since Rohypnol — "roofies" — was outlawed in 1996.
"Ambien has replaced roofies as the rape drug of choice," said Todd Emanuel, a California attorney who has worked on similar rape cases. "It is very easy to secrete in liquid like wine, and it has a short half-life, so it is usually difficult to detect."
Zolpidem generally is not detectable in alleged victims through blood or urine tests more than a day or two after a single exposure, though that can vary depending on the person, the dosage and testing limits, said George Behonick, a toxicologist at the AIT Laboratories in Indiana, whose clients include law enforcement. Hair testing can detect it longer but that will be difficult if there's only been one small dosage, Behonick said.
"It is designed to make people go to sleep and quickly exit the body," Behonick said. "That's the whole idea behind it."
The short testing window, as well as the drug's legality, complicate the criminal cases.
Prosecutors in Los Angeles assert that the narratives recounted by Sharper's alleged victims across the country show an undeniable pattern, even if the women cannot recall much of what happened because of the amnesia-like effect of the drug. While Sharper remains under investigation for alleged rapes in Louisiana, Nevada and Florida, he has been charged only in Arizona and California — cases in which prosecutors have witnesses to bolster victims' accounts.
Los Angeles prosecutor Stacy Okun-Wiese told the judge presiding over Sharper's case that she had listened to recorded statements from witnesses and said "it's like listening to the same person over and over again."
"He is out there preying on women between the ages of 20 and 23 years old. He hangs out with them at clubs. He takes them back, and it's the same story in every single case," Okun-Wiese said.
Sharper faces more than 30 years in prison on the charges in California, which will try its case before Arizona's. His attorneys say he is innocent and note the cases involve women who were out drinking with him.
They also counter in court documents that Sharper has a valid prescription for Ambien but assert that "no Ambien was detected in any of the alleged victims." Any sexual contact that occurred was consensual, said Leonard Levine, one of Sharper's attorneys.
In 2012, a man in Kansas City, Mo., was sentenced to 245 years in federal prison for drugging and molesting 13 children after he admitted to spiking their ice cream and soft drinks with sleeping pills, including zolpidem. Last year, a male nurse in Hawaii was sentenced to two years in prison after being accused of using the drug to spike the beer of a Coast Guard sailor and then sexually assault him.
In 2011, a jury in a civil trial awarded a woman $405,000 in damages after she said her husband, a venture capitalist in Silicon Valley, sexually assaulted her after spiking her wine with zolpidem.
For a number of hours after taking the drug, "you might not recall some or all of what happens," said David Spiegel, a doctor and professor at Stanford University. "You are less likely to recall details of what happened."
Rohypnol had a similar effect and even became known as the "forget pill." It has been used to treat insomnia in other countries, including Mexico, but it was never approved for medical use in the USA. In 1996 it was banned for importation after it became known as an effective tool for date rapists, who often slipped it into the drinks of their victims to knock them unconscious. GHB was another drug used to similar effect, but it was banned in the USA in 1990 before being approved in 2002 to treat a rare form of narcolepsy.
But zolpidem is a prevalent prescription drug and therefore easier to obtain for illegal use. Ambien was approved by the Food and Drug Administration in 1992 and soon became a popular remedy for insomniacs, even though its official guidelines have changed in response to reports of adverse effects on users.
FDA guidelines warn zolpidem users that they might "get out of bed while not being fully awake and do an activity that you do not know you are doing. The next morning you may not remember that you did anything during the night."
"You have a higher chance for doing these activities if you drink alcohol or take other medicines that make you sleepy with Ambien," the guidelines state. "Reported activities include: driving a car, making and eating food, talking on the phone, having sex."
Last year, the FDA notified manufacturers that the recommended zolpidem dosage should be cut in half for women, who generally metabolize the drug more slowly than men and might feel more pronounced side effects. From 2005 to 2010, the number of female visits to the emergency room involving zolpidem increased from 3,527 to 13,130 — double the amount for men, according to the Substance Abuse and Mental Health Services Administration.
In a statement, Ambien manufacturer Sonafi said, "We speak with one voice with the FDA on Ambien's indications." The statement noted that FDA's Medication Guide approves of Ambien for "short-term treatment of a sleep problem called insomnia (trouble falling asleep)" and that Ambien "is a federally controlled substance because it can be abused or lead to dependence."
The company said "short-term is defined as three to four consecutive weeks."
Long-term side effects can include withdrawal agitation, sleep interruption, depression, poor peak performance and focal amnesia, Spiegel said.
"People do get habituated to it," he said. "They do get dependent on it, so you get kind of a rebound effect when you try to stop."
Sharper was far from the first former NFL player to try zolpidem to cope with insomnia. Phil Olsen, 65, a former lineman for the Los Angeles Rams, estimates he's been taking the drug for at least seven years.
"If I don't get my prescription refilled, or if I'm traveling and I forget to bring it, I have a real hard going to sleep without it," Olsen said. "I think you do develop a dependency on it."
George Visger, 55, a former lineman with the San Francisco 49ers, said he has had multiple brain surgeries that he said were necessary because of football-related injuries. He now runs a brain-injury consulting business and said zolpidem use is common among former players because "the sleep issue is huge for us."
Visger said he's been taking the drug, off and on, for several years. Sometimes he's taken one pill at night and then another one a few hours later if he still has trouble sleeping.
To Visger, Sharper's rate of use in recent months doesn't seem strange. "Seventy (pills) in 65 days would be normal," Visger said.
TOUGH TO PROVE
To a sexual predator, zolpidem holds appeal: Not only can the drug be possessed legally with a prescription, it can knock a woman unconscious and leave her unable to know or remember what happened.
"The perpetrator has two things going for him to start off with," Emanuel said. "One is the half-life of the drug (which makes it hard to detect after a day or two), and the other is there are no eyewitnesses."
That's what distinguishes the cases in which Sharper has been charged. In one of the Los Angeles incidents, Sharper allegedly invited two women he was out with Oct. 30 to his hotel room, where he spiked their drinks. Both women passed out, but one of them woke up naked with Sharper raping her. The other woman also woke up and "interrupted his actions," according to court documents filed by prosecutors.
In Arizona, where a grand jury indicted Sharper on felony date-rape charges, Sharper allegedly drugged three women in a Tempe apartment. One woman said she went to the bathroom because she felt ill and became alarmed when she saw Sharper naked on top of a second woman, a police report said.
A third woman said she later woke up naked from the waist down and had no memory of how her clothing was removed. When the woman confronted Sharper about it, the police report quotes Sharper as responding, "I don't really remember. I guess I could have done that. I'm really sorry." The police report said the woman "was not sure ... she wanted to aid in prosecution."
Police in Tempe also said that testing revealed the presence of zolpidem in a cup Sharper used to give drinks to the women. Becaiuse zolpidem generally comes in pill form, it would need to be ground into a powder to dissolve quickly in a drink.
Sharper's attorneys attributed the test result to his prescription. "The Ambien residue found in one cup in one of the cases is entirely consistent with Mr. Sharper's lawful use of Ambien," they wrote in court records.
Emanuel acknowledged the difficulty of proving cases in which victims are drugged. In the case of the woman who said her husband drugged her with it, the woman "actually caught him putting a powder into a glass of wine," said Emanuel, who represented the woman. "I think there needs to be a lot more awareness of this as a date-rape drug. I'm getting calls from wives saying, 'My husband did it.'"