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Most people facing a sex crime allegation in Nevada don’t meet their first detective at an arrest. They meet one on the phone, asked to “come in and clear a few things up,” weeks or months before anyone files a charge. By the time an arrest happens, a Las Vegas Metropolitan Police Department detective has often already collected a forensic exam, pulled phone records, and recorded a call between the accuser and the person under investigation.
We at The Defense Firm represent people through every stage of a sex crime investigation. The stage that decides the most is usually the one nobody warns clients about: the weeks before an arrest, when the state builds its case, and the accused has no attorney and no obligation to help. This guide walks through how a Nevada sex crime investigation moves, what a detective can and cannot do, and where the statute of limitations still governs cases that open years after the alleged conduct. Our companion guide to sexual assault defense strategy in Nevada picks up once charges exist; this one covers everything that happens first.
The Opening Stage of a Sex Crime Investigation in Las Vegas
A report filed within seven days of an alleged incident goes through 911 and gets an immediate response from a patrol officer, according to LVMPD’s own description of its Sexual Assault Unit. Reports made later than that window get taken in person at any Area Command. Either way, the file lands with one of five detective squads assigned to sex crimes, three working day shifts and two working nights, so the unit has coverage every day of the week.
From there, one detective owns the case. That detective decides the timing of the forensic exam, schedules the accuser’s interview, and directs whatever crime scene work still applies. None of this requires a warrant or an arrest. The suspect doesn’t even have to know an investigation exists. Our page on how police investigate sex crime allegations in Las Vegas covers the department’s process in more depth. Our guide to the start of a sexual assault investigation in Nevada walks through the reporting side from the accuser’s perspective.
This gap between report and arrest is not wasted time on the state’s side. Detectives use it to build the file: the exam, the interview, the digital records, and any surveillance footage. A defendant who assumes nothing is happening because no one has knocked on their door is usually wrong. Our overview of reporting sexual assault in Nevada, step by step, shows the same sequence from the other direction.
The SANE Exam and the Forensic Interview
A sexual assault forensic exam happens as close to the alleged incident as the accuser is willing to go through it. Nevada’s own Sexual Assault Nurse Examiner guidance from the state nursing board notes the exam stays medically useful for three to five days afterward. A SANE nurse, not a police officer, conducts it: consent first, then an interview to document the account, then evidence collection covering injuries, biological material, and anything relevant to the timeline.
Nevada law puts one specific limit on how that interview happens. Under NRS 171.1228, no officer, prosecutor, or government employee may require or even request that an accuser take a polygraph as a condition of investigating the report. That protection exists because a lie-detector requirement would discourage reporting, and it applies regardless of how the case resolves. It also says something useful about the exam itself. The account a SANE nurse documents is not screened for consistency at the moment it’s given, so the raw interview record often looks different from the version that surfaces later in a police report.
The kit itself moves through Nevada’s own tracking system after collection. That system is part of the state’s ongoing work through the Sexual Assault Kit Initiative to clear a kit backlog that has shrunk over recent years but has not disappeared. What that kit shows, and what it doesn’t, becomes a defense question once charges exist. Our guide to Nevada’s sexual assault legal process covers how a forensic evidence timeline gets checked once that stage arrives.
The Tactics Detectives Use Before an Arrest
Two techniques show up in nearly every sex crime investigation before an arrest happens. The first is the pretext call, sometimes called a controlled call. A detective sits with the accuser while she or he calls the person under investigation and records the conversation, hoping to obtain an apology, an admission, or any statement that could sound like an acknowledgment of wrongdoing. These calls are usually planned, with officers helping the accuser decide what questions to ask and how to keep the person talking.
The second technique involves collecting digital evidence, including text messages, location history, social media activity, and information stored on mobile applications. Investigators may obtain this material before an arrest and, in some cases, before the person under investigation even knows a detective is reviewing the case. Depending on the circumstances, police may seek access through consent, a subpoena, a search warrant, or records obtained from a service provider.
An informal phone call asking someone to “stop by the station” belongs in this same category, and it can sound far more casual than it actually is. A detective may document anything said during that conversation, including explanations or denials, and those statements can later become part of the investigative file or be introduced as evidence at trial.
Your Right to Refuse During the Investigation
The Fifth Amendment right against self-incrimination applies before an arrest exists, not only after. A person under investigation can decline an interview, decline a request to “come in,” and decline to answer a detective’s questions over the phone, and none of that refusal counts as evidence of guilt. Prosecutors cannot stand in front of a jury and argue that silence proves anything.
Miranda warnings work differently than most people assume, and this is where a lot of damage happens. Miranda only attaches to custodial interrogation, meaning the person has to be both in custody and being questioned. A voluntary pre-arrest conversation, even one that happens at a police station, often falls outside that definition, so nothing requires a detective to read any rights before it starts. Our guide to custodial interrogations conducted without Miranda warnings explains the legal line in detail.
A person under investigation can also retain a criminal defense attorney before any charge exists. Once that happens, the attorney becomes the point of contact with detectives, and the informal calls and interviews stop. Declining to participate is not the same as having something to hide. Our resource on why silence isn’t guilt in a sex crime accusation walks through why the instinct to “just explain your side” so often backfires before an attorney is involved.
From Investigation to Arrest Through a Warrant or Warrantless Arrest
A sex crime investigation ends in one of two ways. A detective can take the file to a magistrate, who reviews a sworn complaint or affidavit and decides whether it establishes probable cause under NRS 171.106. If it does, the magistrate issues an arrest warrant. Alternatively, an officer can make a warrantless arrest on the spot under NRS 171.124, which Nevada law permits for a felony or for conduct committed in the officer’s presence. Most sex crime cases that develop over weeks of investigation end with the warrant route, since the evidence gets assembled before anyone moves to take a person into custody.
Once an arrest happens, a fixed clock starts that never applied during the investigation. NRS 171.178 sets a deadline for bringing an arrested person before a magistrate for a probable cause hearing, and the Nevada Supreme Court, applying the United States Supreme Court’s decision in County of Riverside v. McLaughlin, held that the outer limit is 48 hours, counting weekends and holidays, not the 72 hours the statute’s text describes. That is the only hard deadline in this entire process. Everything before it, from the exam and the interviews to the digital pulls and the pretext call, can take weeks or months with no equivalent limit.
The Statute of Limitations Under NRS 171.095 and Its Effect on the Investigation
A sex crime investigation sometimes opens on conduct alleged from years earlier, and NRS 171.095 is the reason that’s legally possible. For a child victim, the state must file charges before the accuser turns 36, if the abuse was discovered or reasonably should have been discovered by that age, or before turning 43 if discovery took longer. That’s a longer window than most people expect, and it means an investigation into decades-old conduct can still be active and can still produce an arrest.
A related rule removes the deadline entirely. If the accuser files a written report with a law enforcement officer at any point during the limitation period described in NRS 171.083 and NRS 171.085, the clock stops. No time limit remains on when the state can charge the case. The 20-year window for adult sexual assault cases comes from NRS 171.085, not from the exception statute itself, a distinction worth getting right since the two provisions do different jobs.
FAQ
Do detectives have to tell you that you are under investigation?
No, Nevada law does not require an officer to notify a suspect that a case is open, and most people first learn about one through a phone call asking them to come in and talk. That call is part of the investigation, not a courtesy heads-up, and it deserves the same caution as any other contact with a detective.
Can you refuse to talk to a detective before an arrest?
Yes. The right against self-incrimination applies whether or not an arrest has happened, and declining an interview cannot be used against you as evidence of guilt. A detective can keep investigating without a statement from the person under investigation, and often does.
How long can Nevada police investigate a sex crime before making an arrest?
There’s no fixed deadline on the investigation itself. Cases can run for weeks or months while detectives wait on forensic results, digital evidence, and witness interviews. The only fixed clock in this process starts after an arrest, when the state must bring the person before a magistrate for a probable cause hearing within 48 hours.
Conclusion
A Nevada sex crime investigation can advance for weeks or months before an arrest, often while detectives collect forensic evidence, digital records, witness statements, and recorded conversations without notifying the person under investigation. A voluntary interview, pretextual call, text message, or informal explanation can become part of the prosecution’s case long before formal charges are filed. Acting early allows a defense attorney to control communication with law enforcement, preserve favorable evidence, identify inconsistencies, and challenge investigative tactics before the state’s version of events becomes the only one in the file.
If a detective has contacted you, asked you to come to the station, or attempted to discuss a sexual assault or sex crime allegation, do not face the investigation alone or assume that cooperating will make the matter disappear. The attorneys at The Defense Firm can communicate with investigators on your behalf, evaluate the evidence already being collected, and begin building a defense before an arrest occurs. Contact The Defense Firm for a free, confidential consultation before making any statement that could affect your freedom, reputation, and future.