The entire Criminal Procedure Law revolves around the central concept of evidence—essentially, it focuses on how evidence is obtained, presented as a defense, and used to mount an attack. In fact, every stage of a criminal case, from investigation and prosecution review to trial and defense, involves the meticulous search for and examination of evidence. According to the provisions of the Criminal Procedure Law, public security agencies, as investigative authorities, are naturally authorized to gather and examine evidence. Similarly, the procuratorates and courts, as judicial bodies, also have the power to conduct such investigations. But can lawyers themselves investigate and collect evidence? The answer is yes. Yet, many lawyers hesitate—or even refuse—to engage in this crucial task. At the root of this reluctance lies a fundamental misunderstanding of the legal procedures governing lawyers' ability to gather evidence. As a result, numerous ambiguities and challenges remain regarding this essential process.

I. What is lawyer-led investigation and evidence gathering?

The right to investigate and gather evidence is a fundamental litigation right of lawyers, enabling them, during the handling of criminal cases, to obtain, collect, and verify evidence that can prove the suspect or defendant's innocence, mitigate their guilt, or even lead to the exemption or reduction of their criminal liability. Article 43 of China's Criminal Procedure Law stipulates that defense attorneys, with the consent of witnesses or other relevant organizations and individuals, may collect materials related to the case from them. Additionally, they have the right to request the People's Procuratorate or the People's Court to gather or retrieve evidence, or to ask the court to summon witnesses to testify in court. Defense attorneys may also, with permission from the People's Procuratorate or the People's Court—and with the consent of victims, their immediate family members, or witnesses provided by the victims—collect materials pertinent to the case directly from these parties.

In my opinion, lawyer-led fact-finding investigations have the following key characteristics.

1. Lawyers conducting evidence investigations do not have legal enforceability.

Investigations and evidence collection conducted by public security, procuratorial, and judicial personnel are backed by the state’s authority and thus carry mandatory force. Article 54 of the Criminal Procedure Law explicitly grants people’s courts, the People’s Procuratorate, and public security organs the power to gather and request evidence from relevant organizations and individuals. These entities and individuals are legally obligated to provide evidence truthfully. As this provision clearly demonstrates, the ability of authorities to "require" evidence stands in stark contrast to a lawyer’s right to "request" evidence—where compliance is not mandatory but rather contingent upon mutual agreement. Moreover, while investigators armed with officially stamped investigation warrants must receive cooperation from the targeted organizations and individuals—or risk facing adverse consequences—lawyers’ efforts to collect evidence are essentially advisory in nature, lacking any coercive element. Even when gathering information from victims, lawyers often need prior approval from either the court or the procuratorate. Consequently, without the consent or permission of the other party, lawyers frequently find themselves unable to proceed smoothly with their investigative tasks. At the same time, lawyers engaging in evidence collection also face significant risks: under Article 306 of the Criminal Code—the crime of obstructing testimony committed by defense counsel—this legal provision looms like a Damoclean sword over lawyers, constantly limiting their ability to conduct thorough investigations. Taken together, these factors collectively contribute to the persistent challenge lawyers encounter when attempting to gather evidence—a reality that underscores the complexities and constraints inherent in the legal profession today.

Nevertheless, the defense attorney's investigative actions are still considered authorized and legally valid. Under the prescribed legal procedures, lawyers may, with consent or permission, conduct investigations and gather evidence from witnesses and victims. If the person being investigated objects, the defense attorney can still explain the reasons to the procuratorate or court, requesting them to collect and obtain the relevant evidence—or even file a motion asking the court to compel the witness to appear in court and testify.

2. Evidence-Gathering Authority and Its Relativity During the Investigation Phase

During the investigation phase, the defense counsel hasn’t yet had the opportunity to review case files—but do they have the right to conduct investigations and gather evidence? On this point, the law doesn’t provide explicit regulations, unlike the prosecution review or trial stages. Article 38 of the Criminal Procedure Law merely stipulates that defense lawyers may offer legal assistance to the suspect during the investigation, file appeals or complaints on their behalf, request changes to coercive measures, inquire about the alleged charges and relevant details of the case, and submit their opinions.

However, from the original intent of the law, lawyers are indeed entitled to gather evidence during the investigation phase. Article 42 of the Criminal Procedure Law stipulates that if a defense attorney collects evidence showing the suspect was not at the crime scene, had not reached the age of criminal responsibility, or is a mentally ill person legally exempt from criminal liability, the attorney must promptly inform the public security authorities and the People's Procuratorate. Here, "collect" refers to investigative evidence gathering, and "promptly informing the public security authorities" specifically indicates the stage of the investigation.

So, can lawyers conducting investigations and gathering evidence during the investigation phase feel completely free to act? I believe it’s still quite different from the prosecution review and trial stages—otherwise, the law wouldn’t be so cautious and ambiguous. During the investigation phase, legislative and judicial authorities remain concerned that lawyers’ investigative activities might disrupt the normal investigative work of public security organs, potentially interfering with ongoing probes. As a result, while lawyers aren’t actively discouraged from gathering evidence, their right to do so isn’t explicitly endorsed either. After all, if lawyers obtained exculpatory or non-criminal liability evidence directly from companies or family members but were then hesitant to share it with the police, they’d risk leaving critical information hidden until the courtroom—and potentially embarrassing investigators in the process. This clearly shows that, although lawyers do have the right to gather evidence during the investigation phase, this right comes with significant limitations. Moreover, there’s a legal risk involved: improperly handling evidence could even lead to obstruction of testimony. The best approach, once favorable evidence for the suspect is discovered, depends on the type of evidence involved. For testimonial evidence like witness statements, lawyers can use it as a lead to request the public security authorities to verify and collect further proof—but this method carries risks, since investigators might alter the facts during the verification process if they resort to threats or inducements. On the other hand, when dealing with documentary, physical, or electronic evidence, lawyers are better positioned to directly obtain it themselves, perhaps by collaborating with notaries, forensic experts, or specialized online evidence preservation organizations to ensure reliable collection.

Additionally, investigative evidence gathering by public security authorities is characterized by a "wide-net approach," collecting all types of evidence relevant to conviction and sentencing—including both evidence favorable and unfavorable to the suspect. In contrast, criminal investigations conducted by lawyers tend to focus specifically on gathering evidence that benefits the defendant. This is because, in line with their legal duty to "safeguard the legitimate rights and interests of their clients," lawyers must prioritize identifying facts and arguments that can prove the suspect or defendant’s innocence, mitigate charges, or even lead to exemption from criminal liability. Lawyers should avoid seeking or compiling evidence that might harm their clients—doing so would blur the boundaries of their advocacy role, potentially turning them into an "unofficial second prosecutor" and undermining their ability to protect their clients’ rights as well as ensure the fair application of the law. From this perspective, a lawyer’s professional expertise becomes absolutely critical; after all, high-level professionalism helps prevent the unfortunate mistake of treating evidence detrimental to the suspect as if it were actually beneficial—and subsequently presenting it as such.

II. Types of Evidence in Investigation and Evidence Collection

The objects of evidence gathering by lawyers broadly correspond to the types of evidence defined in litigation law.

1. Physical Evidence

When it comes to objective evidence such as physical or documentary proof, lawyers often find it challenging to obtain these materials—especially if they require cooperation from other departments or individuals beyond what the client or parties involved can directly provide. Moreover, prosecutors and courts typically hesitate to support such requests. Even when certain "connections" help secure partial access to resources like bank records, tax documents, or call logs, the legality of how these materials were obtained often comes under scrutiny, making it difficult for them to serve as valid evidence in criminal proceedings. The only viable solution, therefore, is to treat these as mere leads and persistently—and vigorously—urge the court to take steps that ensure the admissibility and reliability of the evidence.

2. Statement by the Parties

The statement made by the当事人 (the person involved) differs from what a defense lawyer presents, but for public prosecution, investigation, and judicial authorities, it is considered a "confession." Broadly speaking, the当事ent's statement also forms the basis of the lawyer's investigative efforts to gather evidence. In criminal cases, each meeting between the defense lawyer and the当事人 essentially constitutes an investigative act aimed at collecting relevant information. Therefore, lawyers must carefully prepare detailed meeting records during these sessions, accurately documenting the statements made by the suspect or defendant, and ensure that the individual signs off on the record to confirm its accuracy—this documentation can then serve as crucial evidence in court.

Lawyers must fully harness their legal authority, boldly gather evidence, and at the same time remain vigilant in managing risks. For instance, some witnesses may be unable to appear in court, yet their testimonies are critically important—so lawyers have no choice but to collect this evidence directly from them, as long as they carefully prioritize the safety of their取证 methods.

When conducting formal evidence collection, it’s best to start video or audio recording as soon as you meet with the individual. The evidence-gathering process should be carried out by two lawyers, who must present their identification and proof of affiliation with their law firm. Additionally, you may invite an unrelated person to serve as a witness, but neither the当事人 nor their family or friends can be present. During the investigation, avoid discussing assets or items unrelated to the case altogether, as this could raise suspicions of influencing the witness. Finally, ensure that the details of the investigation are accurately documented in a written record, which should then be reviewed and signed by the witness for confirmation.

In situations where investigation and evidence collection are unsuitable or impossible, you can also opt for some appropriate alternative methods. For instance, you might provide clues of evidence to judicial authorities, or request the procuratorate or court to gather evidence officially—while a lawyer can be present during this process. Alternatively, the client may choose to collect evidence independently, without direct involvement from the lawyer. For example, the client could ask relevant individuals to write a "statement of circumstances," or have a company issue an official "certificate"—and so on. However, it’s important to note that evidence obtained through these methods may not be flawless in terms of its source, legality, or authenticity. Additionally, such evidence often lacks specificity, which could significantly weaken its probative value in legal proceedings.

Lawyers can conduct a validating on-site investigation of the crime scene based on inconsistencies and potential falsity in the victim's statement and witness testimonies. In a recent organized-crime case in Harbin, we visited the location where the group brawl allegedly took place. Through our on-site examination, we discovered that, from the vantage point occupied by the witnesses, it was entirely impossible to see what was happening on the street outside the courtyard—thus proving the witnesses' statements were false.

Lawyers can also conduct their own rebutting investigations into the on-site examinations, inspections, and identification records made by public security authorities, using factors such as the time of arrival at the scene, travel routes, and the actual conditions present, to demonstrate that the authorities' records lack objectivity.

5. Expert Opinion

Like investigative authorities, lawyers can also hire expert appraisal institutions to conduct expert evaluations—or even counter-expert assessments—on specialized issues relevant to the case. Even if the appraisal institution doesn’t provide its findings in the form of an official opinion but instead submits documents such as reasoned arguments, these still carry significant weight in court. Adding an expert witness to the proceedings, who can clarify the contents of the expert report and directly challenge the prosecution’s appointed expert during cross-examination, can further enhance the effectiveness of this approach. Typically, the law firm representing the client should be responsible for signing a contract with the appraisal institution and issuing a formal written commission. It’s especially important to avoid letting the client’s family members independently engage the appraisal service, as this could undermine the evidentiary value of the submitted materials.

6. Audiovisual Materials

Photos, videos, and other materials related to the case can all serve as audiovisual evidence—and these pieces of evidence can even be collected by lawyers. In recent years, this type of evidence has been vividly and widely applied in criminal cases. For instance, in a gang-related case in Yunnan, several lawyers personally took to the streets to conduct random interviews with residents in the areas involved, gathering firsthand insights into the defendant’s alleged social harm. The continuous, comprehensive, and uninterrupted video footage captured during these interviews was submitted to the court as audiovisual evidence and was played directly in court—yielding remarkable results.

Lawyers can also independently gather counter-evidence—such as audiovisual materials, inspections, and records—from the public security authorities. For instance, they can use data from mobile phones or computers to demonstrate the time of arrival at the scene, the route taken, and the actual conditions on-site, thereby challenging the objectivity of the public security authorities' audiovisual evidence.

7. Electronic Data

In the information age, electronic data has become the king of evidence, appearing in most cases—whether it’s emails, WeChat chats, or transaction records. Increasingly, in cybercrime cases, electronic data serves as the central piece of evidence, subject to stringent procedural rules and technical requirements throughout processes like extraction and examination. Lawyers can play a crucial role in areas such as electronic data retrieval and blockchain-based evidence preservation, often collaborating closely with technical teams to ensure timely and reliable evidence collection.

III. Methods for Investigation and Evidence Collection

As previously mentioned, lawyers are legally entitled to investigate and gather evidence—but they often face significant practical challenges as well as legal risks. This reluctance among most criminal defense attorneys to conduct their own investigations, instead choosing to rely solely on the evidence handed over by investigative authorities, has, to some extent, undermined the effectiveness of their defense strategies.

Lawyers must fully leverage their legal authority, boldly gather evidence, and at the same time remain vigilant in managing risks. For instance, some witnesses may be unable to appear in court, yet their testimonies are critically important—so lawyers have no choice but to collect this evidence directly from them, as long as they carefully prioritize the safety of their取证 methods.

For example, when gathering evidence from a witness, it’s crucial to avoid any prior contact with the witness altogether—this includes phone calls, meetings, or even sharing meals. Ideally, you should meet the witness directly during the evidence-gathering process, or alternatively, communicate via text message to leave a clear record of your interaction. At the same time, make sure to prevent the witness’s family members from speaking to the witness beforehand, as this could lead to them influencing the witness to alter their testimony or even provide false statements.

When conducting formal evidence collection, it’s best to start video or audio recording as soon as you meet with the individual. The evidence-gathering process should be carried out by two lawyers, who must present their identification and proof of affiliation with their law firm. Additionally, you may invite an unrelated person to serve as a witness, but neither the当事人 nor their family or friends can be present. During the investigation, avoid discussing assets or items unrelated to the case altogether, as this could raise suspicions of influencing the witness. Finally, ensure that the details of the investigation are accurately documented in a written record, which should then be reviewed and signed by the witness for confirmation.

For instance, when collecting physical or documentary evidence, it’s important to understand the nature of the evidence and trace its origin to verify its authenticity. Whenever possible, prioritize obtaining the original documents; if the originals cannot be retrieved, consider taking photographs, making copies, or recording videos instead. Be sure to document the location where the originals are stored, as well as information about their current holder.

For situations where investigation and evidence collection are unsuitable or impossible, you can also opt for some appropriate alternative methods. For instance, you might provide线索 (clues) of evidence to judicial authorities, or request the procuratorate or court to gather evidence officially—while a lawyer can be present during this process. Alternatively, the client may choose to collect evidence independently, without direct involvement from the lawyer. For example, the client could ask relevant individuals to write a "statement of circumstances," or have a company issue an official "certificate"—and so on. However, it’s important to note that evidence obtained through these methods may not be flawless in terms of its source, legality, or authenticity. Additionally, such evidence often lacks specificity, which could significantly weaken its probative value in legal proceedings.