Nearly eight months after a University of Maryland student was killed crossing Route 1, a private investigator hired by her family is raising questions about the circumstances surrounding her death. While police are still investigating the case, they have largely contradicted the investigator’s statements.

Freshman Maria Fisher was hit by an SUV early in the morning of Oct. 1 near the intersection of Campus Drive and Route 1. She was taken to the hospital, where she later died. A Prince George’s County Police spokesperson told The Diamondback the department does not currently suspect foul play.

But a news release issued May 15 by Spaulding Security and Investigations, the security firm hired by the Fisher family to investigate the accident, raised concerns about Fisher’s toxicology report and her whereabouts before she was hit.

[Read more: “She exuded kindness”: friends and family remember UMD student Maria Fisher]

“Maria had left several messages for fellow students, advising one she had woken up in a strange room and could not remember what had happened the night before,” read the release, which was posted around the campus as well as on Spaulding’s Facebook page. “Maria’s toxicology report showed a high level of the drug GHB.”

GHB is a central nervous system depressant that can cause euphoria and the loss of consciousness in large doses. It can be used as a “date rape drug” or “party drug,” but it also occurs naturally in the body, where it functions as a neurotransmitter. Studies have shown that its concentration in the body can increase after death.

According to Prince George’s County Police spokesperson Jennifer Donelan, the amount of GHB found in Fisher’s system at the time of her death was consistent with the natural amount found in a person’s system postmortem. Donelan also confirmed that an autopsy had been performed, and there was “absolutely no evidence” Fisher had been sexually assaulted.

[Read more: Maria Fisher’s friends and family have raised more than $13k for scholarships in her honor]

When contacted Monday, Dan Fisher, Maria Fisher’s father, indicated he still had concerns regarding his daughter’s GHB levels, which is why the police department agreed to further investigate the events before her death.

“My understanding … of the GHB levels is different than that of the police department,” he said in a text message. “So we agreed to look into it further.”

The Spaulding post on Facebook was later updated to indicate “it is NOT clear whether this GHB was ingested prior to death, or occurred naturally after death (the police and family continue to research this issue).”

Private investigator Bill Nutter, who is investigating the case, said his company made the changes to the flyer at the request of Prince George’s County Police and the Fisher family, but stands by the original wording.

Fisher said his family opted to contact the private investigation firm in early May, since they felt the police investigation was not answering some of their questions about the events prior to Maria’s death.

PGPD’s traffic enforcement unit and sexual assault unit have carried out the investigation, which is not yet complete, Donelan said.

“We met with the father on Friday,” Donelan said. “And he’s asked us to look into some things, so we’re going to do that. We want to make sure that we’re addressing his concerns.”

Fisher’s father said some of his concerns also stem from his daughter’s phone records.

“She was coherent and not obviously drunk at approximately 2 a.m., and then all of the sudden her texts became incoherent and she kind of went off the radar,” he said.

Investigators have spoken with individuals who were in contact with Fisher before her death, and intend to speak with more as they continue their investigation, Donelan said. The department is still investigating Fisher’s cell phone messages, she added.

The investigation is largely about accounting for the time between about 2 a.m., when Fisher stopped responding to text messages from friends, and about 6 a.m., when she contacted them again, her father said.

“We’re not trying to accuse anyone — we just want to know, did someone see her drunk and walk her to a place where she could sleep and then she woke up unfamiliar [with her surroundings] or what happened? Where was she? We’re just looking for closure,” Fisher’s father said. “We just want to know what happened to her.”