"This appears to be a horrific accident," Riverside County Sheriff Chad Bianco told the Denver Post. "And unfortunately for all of those involved, one of the people – well, a couple of them – happen to be very high-profile celebrities. And that makes this more of an issue than it probably should be."
Elway, who played his whole career on the Denver Broncos, issued a statement saying he was devastated by the loss of his close friend.
Here is what we know about the incident.
What happened last weekend?
Riverside County fire authorities were called to The Madison Club, an upscale country club and residential community in the desert community of La Quinta near Palm Springs, on Saturday evening for a report of a person suffering serious injuries after falling off a golf cart.
Sperbeck was then taken to the hospital, and he died early Wednesday from his injuries.
Elway was at the scene of the crash, witness Ali Simon told KESQ-TV. Simon said she did not see the accident occur, but saw a man lying on the ground surrounded by people and Elway on the phone.
TMZ has reported that Elway was driving the golf cart, citing unidentified sources. KUSA-TV in Denver also cited an unnamed source saying Elway was driving.
Law enforcement officials have not said who was driving the golf cart, and Elway did not confirm or deny it in a statement about Sperbeck's death.
Medical personnel at the scene didn’t find evidence suggesting Elway was drunk, Bianco told the Denver Post. He did not elaborate about how personnel reached that conclusion.
What is the sheriff’s office’s involvement?
Bianco said first responders didn't immediately call the sheriff's office to the scene, and typically would notify law enforcement if there were a concern. He said his agency got involved following media interest in the case and is reviewing surveillance footage and witness testimony. The investigation will be short, he said.
Ed Obayashi, Modoc County deputy sheriff and special prosecutor, said law enforcement might not initially be called to investigate an injury involving a single person, for example, who falls down the stairs or from a bicycle.
But if a death occurs, Obayashi said law enforcement officials are typically asked to investigate so the coroner can complete a thorough report.
“It could be a matter of routine, or there may be some information they received that requires them to investigate it,” said Obayashi, who trains law enforcement officials on legal issues.
Elway's attorney, Harvey Steinberg, told Colorado's 9NEWS it was an accident.
“The investigation has confirmed what we already knew: This was a tragic accident and sometimes things happen in life that we will never comprehend,“ Steinberg said.
Who was Sperbeck?
Sperbeck, who is from the Orange County seaside community of San Clemente, began managing Elway in 1990, when Elway was quarterback for the Denver Broncos. He represented more than 100 NFL players during a three-decade career as an agent and business adviser.
He was best known as Elway’s longtime friend, business partner and agent who helped manage the Hall of Famer’s extensive off-field business empire, which included restaurants, car dealerships and a winery.
“We are grieving this unimaginable loss as a family alongside our dearest friends the Elway’s and the many other clients Jeff called friends," the Sperbeck family said in a statement.
Sperbeck managed Elway’s marketing and business ventures, and the two collaborated with winemaker Rob Mondavi Jr. in 2015 to co-found 7Cellars by John Elway. Sperbeck was also involved in numerous charitable endeavors and co-founded a sports marketing firm.
Elway issued a statement following Sperbeck’s death.
“I am absolutely devastated and heartbroken by the passing of my close friend, business partner and agent Jeff Sperbeck,” he said. “There are no words to truly express the profound sadness I feel with the sudden loss of someone who has meant so much to me.”