Michigan State University students walked into Wells Hall for the first day of final exams on April 27, unaware that campus police had investigated a trespasser carrying bottles of unknown substances in the school's largest academic building hours earlier.
MSU's Department of Police and Public Safety arrived at Wells Hall to investigate a report of a “trespasser" at approximately 9:20 p.m. on Sunday, April 26.
There, officers made contact with Xin Tong, a former MSU mathematics graduate student, carrying multiple bags on the fifth floor of the “C” Wing. Tong, 31, would later be arrested on charges of possessing chemicals used in the manufacturing of methamphetamine and malicious destruction of property on April 27.
Tong went on to be found incompetent to stand trial on August 14. His competency review hearing is scheduled for Nov. 13.
But records show April 26 was not the first time police had been called to Wells Hall for suspicious activity. Similar incidents may have started around September 2025, but not reported to DPPS until April 2026, according to case reports obtained through public records requests by The State News.
Wells Hall would eventually be shut down for the remainder of the week on the morning of Monday, April 27, but not before students had already begun taking tests in the building.
The following details are from 68 pages of police reports related to the incident. The documents obtained by The State News through Freedom of Information requests had heavy redactions due to the ongoing investigation.
An "extremely strong 'chemical-type' odor"
The substance, which was unknown at the time, was reported at least five times before Tong was arrested.
On April 11, “staff in Wells Hall noticed an unknown *redacted* substance,” after which DPPS did a walk through of the building with a K-9 dog.
Seven days later, an officer wrote that “this incident occurred a second time, in front of different employee offices.”
An observer told police he had seen someone on April 21 “walking back and forth on the 3rd floor, C wing, of Wells Hall for approximately 20 minutes.” The subject was wearing “a blue latex/nitrile type glove on at least one of his hands” and walked down the hall “with his hands behind his back.”
The next day, more of the “unknown *redacted* substance" appeared in front of faculty offices located in that wing.
“A total of 5 employee offices have had the unknown substance in front of their office doorway, under the door, and slightly into their office,” one officer wrote.
Three days later, on April 23, officers were dispatched to Wells Hall in “reference to a chemical smell on the 3rd floor.” Once on the third floor, an officer wrote he “could smell an extremely strong 'chemical' type odor throughout the floor.”
Inside the building
Surveillance footage reviewed by police showed Tong entering Wells Hall at 9:03 p.m. on April 26 after the building had been electronically secured.
Wells Hall, in accordance with security upgrades made after the Feb. 13, 2023 mass shooting, electronically locks at 6 p.m. Monday through Friday and is closed on the weekends.
Tong was “seen circling the building, trying different doors, not able to get in”, but eventually followed behind someone with access to the building.
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Officers were told to look for an “Asian Male" with "long hair" and "black teeth.” Tong was found on the fifth floor of the “C” wing, where an officer wrote he could “smell a faint, unknown chemical odor.”
DPPS spokesperson Nadia Vizueta wrote in a statement to The State News that officers then seized some of Tong's personal property “believing that he may be a suspect in other crimes." The seized materials were taken back to the MSU Police Department to obtain a search warrant from a judge so officers could "legally search his personal property,” Vizueta said.
Within Tong's belongings, police found items like bottles with an unidentified “substance inside,” N95 masks and scissors.
After finding him on the third floor of the building, police struggled to communicate effectively with Tong. One officer attempted to determine whether Tong would better understand another language, but several attempts to use a language interpreter failed. Tong eventually said he understood English and provided a verifiable ID.
Tong was carrying an expired MSU student ID when he was confronted, according to court documents.
Law enforcement often uses interpretation services to bridge communication gaps with non-English speaking individuals, which, in this case, "failed," according to a report.
There, during a conversation when Tong was wearing rubber gloves, officers issued him a misdemeanor appearance, citation and removed him from campus, according to DPPS.
“At that time officers had probable cause for a misdemeanor trespassing charge, which was only a citable offense under the circumstances at the time," Vizueta said.
Officers also recorded damage to tiles and doors within Wells Hall, with an estimated total cost of damages being $100,000.
Securing Wells Hall
Wells Hall, where Tong was reprimanded just hours prior, was open as usual the next morning.
Students were in the midst of taking their exams when they got an email from the university as fire alarms begin to sound.
“At the start of the exam, we received a strange email from the university,” computer science senior Justice Yin told The State News at the time. “We weren't really sure if it was like a fire drill or something. They were just like, keep caution, but then the alarms went off, so we quickly evacuated.”
The campus wide email sent out at 10:18 a.m. urged students not to enter Wells Hall due to “some unknown chemicals.”
The building was initially set to be closed for one day, but was then closed for the remainder of the week.
DPPS did not directly answer questions asking why Wells Hall remained open to students that morning, given the events of the previous night. Vizueta said the university decided to close the building so testing could determine whether the environment posed a risk to the community.
“The decision was then made at that time to close Wells Hall so testing could be performed to confirm the environment did not pose a risk to our community," Vizueta said. "This was done out of an overabundance of caution while recognizing the impact it may have on students, faculty and staff."
Vizueta clarified that a judicial search warrant was executed the next morning, which meant that the night before they did not know what the chemicals were, but instead contacted multiple agencies. Those agencies included the Federal Bureau of Investigations, Michigan State Police and MSU Environmental Health and Safety in an effort to identify the substances.
Meaning, when students sat for their first exams of the week on April 27, officials did not yet know what substance was.
Vizueta also did not directly respond to questions regarding the trespassing incidents possibly starting nearly eight months prior in September of 2025.
MSU Spokesperson Amber McCann deferred to Vizueta's comments when asked about the time between students entering the building and when they were evacuated.
Over the following days, investigators identified chemicals in Tong’s possession, including sodium hydroxide pellets, hydrochloric acid, methanol, isopropyl alcohol, acetone and butane, according to MSU police. The university later clarified that investigators never located a meth lab inside Wells Hall, but instead chemicals used to create methamphetamine.
