LAS VEGAS (KLAS) — Las Vegas Metro police arrested a man who threatened a mass shooting at the Stanley Cup Final hours before the Vegas Golden Knights clinched the championship, sources told the 8 News Now Investigators.

Just before noon on Tuesday, police responded to a business near Smoke Ranch Road and Tenaya Way for a report of a person, later identified as Matthew DeSavio, 33, who was threatening a mass shooting at the Stanley Cup Final, documents said.

The person told police DeSavio had stalked them for about a decade, officers said. DeSavio later showed up to the business where officers arrested him, documents the 8 News Now Investigators obtained Wednesday said.

DeSavio also posted threatening messages about the game on Facebook, police said.

Matthew DeSavio, 33, seen here in a prior booking photo, faces a charge of making threats of conveying false information concerning acts of terrorism, among others. (LVMPD/KLAS)

“I’m coming for you guys tonight and I hope you get every [expletive] police officer in Vegas Golden Knights there to defend you!” one message said, according to police. “Hope Sin City is ready for the Mandalay Bay massacre part duex [sic].”

Another person contacted police, seeing Facebook posts where DeSavio “[claimed] to want to conduct a mass shooting at T-Mobile Arena,” police said.

Fifty-eight people were shot and killed during the Route 91 Harvest Festival on Oct. 1, 2017. One October is the deadliest mass shooting in U.S. history. Two people later died from injuries they suffered that night, bringing the death toll to 60. Hundreds more were injured in the shooting.

In another post, DeSavio reportedly wrote, “I warned y’all October 1st was just a preview,” police said.

Members of the Vegas Golden Knights celebrate after they defeated the Florida Panthers 9-3 to win the Stanley Cup in Game 5 of the NHL hockey Stanley Cup Finals Tuesday, June 13, 2023, in Las Vegas. (AP Photo/Abbie Parr)

Police arrested DeSavio outside of the business, about five hours before the game, the 8 News Now Investigators learned.

“As patrol officers were placing DeSavio into the patrol car, DeSavio declared several excited utterances asking if anyone had seen his Facebook posts yet and that the Knights need to win by a certain amount or he will do a repeat of the Mandalay Bay 1 October shooting,” police said.

DeSavio was adjudicated for prior stalking and harassment cases, police said.

In other Facebook posts on Tuesday, DeSavio cited the 8 News Now Investigators’ reporting about his previous arrests.

Police did not note if DeSavio had access to any weapons, though a spokesperson said Tuesday, after DeSavio’s arrest, that they were aware of the threat.

A message on Matthew DeSavio’s Facebook page, cited by police in court documents. (KLAS)

On Oct. 26, 2022, a person reported a “disturbing Facebook post” to police where DeSavio reportedly threatened a similar mass shooting, police said.

“Something big is about to hit the Vegas Strip. #October1stwasjustapreview! Let’s [expletive] [expletive] up before I literally #blowup Paradise NV,” the Facebook post reportedly said, according to police. The Las Vegas Strip is in the unincorporated community of Paradise, Nevada.

Officers later contacted DeSavio, who agreed to meet them at a fast-food restaurant on Blue Diamond Road near Durango Drive, police said. While speaking to DeSavio, police said the man “stated he wanted to drive his vehicle into the Mandalay Bay.”

Records show a judge ordered DeSavio to undergo a competency evaluation in November 2022. DeSavio awaited treatment for 78 days, which his public defender said violated his due process rights.

In a hearing in March, Judge Christy Craig noted the state failed to transport DeSavio to behavioral health treatment in a timely manner. DeSavio remained in custody for eight days after that hearing, prompting Craig to dismiss the charges and release DeSavio from custody in April.

DeSavio faces charges of stalking, making a false threat regarding an act of terrorism, aggravated stalking and violating a temporary protection order for the threats made Tuesday, records show.

He refused to be taken from the Clark County Detention Center to the Regional Justice Center on Wednesday for his initial appearance. A judge did not set bail and rescheduled his court appearance for June 20.