Dennis Geiggar, a teenager identified by local reports as a former student at Valley High School, was taken into custody on May 5 and charged with one felony count of open murder in connection with the death of Marceline Biasini, a woman authorities say was frequently known to sleep in the area where her body was discovered.

The killing has shocked residents across Las Vegas not only because of the victim’s age and vulnerability, but also because investigators allege the attack may have been captured in chilling audio recorded by nearby surveillance systems. Police say the footage did not directly show the fatal assault itself, but investigators reportedly heard what sounded like a scream followed by dozens of loud impact noises in the darkness.

According to the Las Vegas Metropolitan Police Department, officers responded just after 8 a.m. on April 21 after receiving reports of an injured woman lying on a sidewalk outside a local business. Responding officers found Biasini suffering from severe visible injuries. She was pronounced dead shortly afterward.

The Clark County coroner later ruled her death a homicide caused by blunt head trauma, confirming investigators’ suspicions that she had been violently beaten sometime during the overnight hours.

Police documents cited by local media indicate surveillance cameras positioned nearby partially captured the moments leading up to the killing. Investigators say a suspect could be seen approaching the area where Biasini was resting in the middle of the night before leaving roughly a minute later.

Although the exact location of the attack was obscured from direct camera view, detectives reportedly reviewed audio from the surveillance system that captured a horrifying sequence of sounds. According to reports, investigators heard a scream followed by approximately 61 loud impact noises believed to be associated with the beating.

“The precise location of the crime scene was obstructed from surveillance cameras,” police records reportedly stated, “but video surveillance with audio captured the suspect approaching Marceline’s location and, seconds later, a scream is heard followed by approximately 61 loud thuds.”

The brutality described in the investigative documents stunned even veteran investigators, who say the evidence suggests an extraordinarily violent assault against a defenseless victim.

Detectives eventually focused their attention on Geiggar after reviewing surveillance footage from a nearby 7-Eleven convenience store. According to reports, the suspect seen in the footage was wearing a red hooded sweatshirt and Vans shoes — clothing police say matched items Geiggar had frequently worn while attending Valley High School.

Authorities also reportedly discovered bloody footwear impressions near the crime scene. Investigators later tested a pair of Vans shoes linked to Geiggar, with preliminary testing returning presumptive positive results for blood. Officials noted, however, that DNA analysis comparing the blood evidence had not yet been finalized.

Police additionally stated that Geiggar’s physical description matched that of the person seen in surveillance footage near the scene around the time of the killing.

During questioning, Geiggar reportedly denied involvement in Biasini’s death. However, according to court documents referenced by local outlets, he acknowledged being near the area during the early morning hours and told investigators he had gone to a nearby 7-Eleven with his older brother sometime between 1 and 2 a.m.

Investigators reportedly found inconsistencies in that explanation after reviewing store surveillance video, which allegedly did not show him entering the business during the timeframe he described.

The teenager’s background has since drawn significant attention after reports surfaced detailing prior behavioral concerns and anger-related incidents at school. According to the Las Vegas Review-Journal, Geiggar had been expelled from Valley High School earlier this year after allegedly attempting to start a fire on campus.

Following the expulsion, he had reportedly been attending classes online.

Police documents further described a pattern of troubling behavior involving anger management problems. Investigators said Geiggar had been involved in “numerous incidents” in which his anger allegedly resulted in him punching walls, damaging trash cans, and displaying volatile conduct significant enough to require participation in anger management classes.

Despite those reported issues, authorities indicated Geiggar had no publicly known violent felony convictions prior to his arrest in the homicide investigation.

Biasini’s death has reignited conversations in Las Vegas surrounding homelessness, public safety, and mental health support systems for both vulnerable adults and troubled youth. Residents familiar with the area where her body was discovered said the 61-year-old woman was often seen sleeping nearby and was known to some members of the community.

Community advocates have pointed to the devastating vulnerability of individuals living on the streets, particularly older adults who may have limited protection or access to services. The allegations in this case — involving a teenager accused of targeting a sleeping woman — have intensified fears about violence against unhoused residents.

Meanwhile, legal experts note that Geiggar’s age could become a significant factor as prosecutors determine how aggressively to pursue the case moving forward. Open murder charges in Nevada allow prosecutors flexibility in later determining the specific degree of murder allegations based on evidence developed during the investigation.

As of now, authorities have not publicly announced whether they intend to seek adult prosecution or enhanced penalties if Geiggar is convicted.

The teenager appeared briefly in court following his arrest, where he remained in custody as the case proceeds through the legal system. It remains unclear whether he has formally retained an attorney, and no detailed defense strategy has yet been publicly outlined.

Investigators continue analyzing forensic evidence, including the bloody shoe impressions and pending DNA testing results, which could become critical pieces of evidence in court proceedings. Detectives are also reviewing additional surveillance footage and witness statements in an effort to establish a precise timeline of events from the night Biasini was killed.

For now, the killing remains one of the city’s most disturbing recent homicide cases — a brutal attack allegedly carried out in darkness against a vulnerable woman sleeping alone on a sidewalk.

As the case advances, prosecutors will likely face intense scrutiny over how a teenager with a documented history of behavioral instability allegedly escalated to violence of such extreme severity. Meanwhile, family members, investigators, and community residents continue waiting for answers surrounding the final moments of Marceline Biasini’s life and the motive behind the deadly assault that ended it.