In 1998, when I first transitioned into practicing law, the very first case I handled involved illegal marijuana cultivation. As a recent law school graduate, I had studied numerous legal statutes in theory, but it was this first real-world application of the law that enabled me to successfully get the charges dismissed, sparking my lasting interest in U.S. criminal law. Over the past two decades, I have successfully represented and resolved thousands of cases related to illegal marijuana cultivation, helping many Chinese immigrants and families who were arrested for such offenses. 

One day, the Diamond Bar Police Department received a report from a neighbor who suspected that the occupants of a nearby house were illegally growing marijuana inside the residence. Police arrived at the reported address shortly after 8 a.m. and observed that the windows and glass doors of the two-story home were completely sealed. Knocking on the door yielded no response. The neighbor reported that the house was lit 24 hours a day, equipped with ventilation fans, and emitted a strange odor. Upon approaching the property, the officers also detected the smell of marijuana. They then contacted officers to file for a search warrant at the Pomona court. Given the reasonable suspicion based on the odor and the neighbor’s report, the court quickly approved the search warrant. 

A team of over 20 officers forced entry and arrested two individuals on the spot: Mr. Zhou, the homeowner, and Mr. Chen, who was helping with the work. Upon entering the house, the officers discovered approximately 2,000 marijuana plants and over 200 packages of processed marijuana. At that time, California had not yet enacted Proposition 64, and illegal marijuana cultivation carried a prison sentence of more than three years. 

However, while representing Mr. Zhou, we discovered several procedural inconsistencies and issues with the execution of the search. The search warrant was signed at 9:15 a.m., but according to records, the police had already entered the house by 9:25 a.m. Driving from Pomona Court to the gated community in Diamond Bar takes at least 20 minutes, considering the mountainous terrain and security checkpoint. 

During arraignment, we requested that the prosecution provide all documentation regarding the issuance and execution of the search warrant to verify the timing. In the preliminary hearing, we asked the officers whether they had the warrant in hand when they entered the residence. Initially, they claimed they did, but upon further questioning, they had to admit that the warrant had not yet arrived at the time of entry. 

We immediately filed a motion arguing that the officers conducted an illegal search, as they did not have the warrant at the time and had not obtained consent to enter. Consequently, all evidence obtained during that search was inadmissible in court. The judge agreed with our argument, and the charges against Mr. Zhou were ultimately dismissed. However, the charges against Mr. Chen were not dropped, as he was not the homeowner. 

Under the Fourth Amendment of the U.S. Constitution, a homeowner has the right to be free from unreasonable searches and seizures by the government. Any evidence obtained without a valid warrant is inadmissible. Since Mr. Chen was not the property owner, he was not protected under the Fourth Amendment in this context. As a result, the evidence collected was admissible against him. This outcome surprised many reporters at the time: the employer, Mr. Zhou, had his charges dismissed, while Mr. Chen was convicted due to inadequate defense by his court-appointed public defender. Ultimately, the house in question did not belong to Mr. Chen, and the Fourth Amendment does not protect the rights of guests on the property. 

In law school, every attorney is required to study three core subjects: Constitutional Law, Criminal Law, and Criminal Procedure. Many often ask: if the United States already has a criminal code, why is criminal procedure a separate area of study? And how are both related to the U.S. Constitution? 

In fact, U.S. criminal law is a synthesis of these three areas. The amendments to the U.S. Constitution collectively form what is known as the Bill of Rights, which outlines the rights of the people. For example: 

  • The First Amendment guarantees freedom of speech; 
  • The Second Amendment protects the right to bear arms; 
  • The Fourth Amendment protects against unreasonable searches; 
  • The Fifth Amendment grants the right to remain silent; 
  • The Sixth Amendment ensures the right to counsel; 
  • The Eighth Amendment guarantees a speedy trial for the accused. 

These rights are collectively known as “civil liberties.” 

Therefore, in criminal cases, if law enforcement fails to respect constitutional protections during evidence collection, any resulting evidence may be deemed inadmissible. This is why criminal law must always be analyzed in conjunction with criminal procedure—to determine whether the investigation adhered to proper legal protocols. 

In the United States, a criminal case may be dismissed not necessarily because the defendant is innocent, but because law enforcement either failed to collect sufficient evidence or violated legal procedures, resulting in the exclusion of critical evidence.