Bryce Renshaw said he was on his way to nearby trails for a ride when he came upon the crash that killed Matt Peterson, 30, of San Francisco, and Kristy Gough, 31, of Oakland.
"I saw the officer pacing back and forth on the roadway. He said, 'I must have fallen asleep,' " said Renshaw, a chiropractor.
California Highway Patrol investigators have found no evidence that the deputy fell asleep during a routine patrol, officer Todd Thibodeau said.
"We are asking people to avoid speculation and we are avoiding speculating," Thibodeau said. "We are sticking with what we know until the investigation is complete."
Investigators could wrap up their inquiry in as little as 30 days, he said.
Officials have said that the deputy crossed a double-yellow line into oncoming traffic where he struck the group.
Because CHP officers believe there was also no evidence that drugs or alcohol played a role in the crash, Thibodeau said the department did not require a blood sample from the deputy. However, Santa Clara County Sheriff's Sgt. Don Morrissey said it is routine for his department to test blood samples from any employee involved in a major incident.
Morrissey identified the deputy as James Council, 27. He has been with the department for about a year and a half. The deputy, Morrissey said, started his shift at 6 a.m. It was not an overtime shift, Morrissey added. A man who answered the phone at Council's home said the deputy was not taking calls.
It was around 10:30 a.m. Sunday when Council's patrol car crossed the center line on Stevens Canyon Road in Cupertino and drove into the riders.
It is unclear how fast the patrol car was going, how far it crossed the center line and where exactly on the opposite side of the road Council struck the group, Thibodeau said.
"There are a lot of details we are still trying to figure out. 'Why' is going to be a big question," he said.
The crash on a beautiful Sunday morning left the Bay Area cycling community and the sheriff's department shaken. Coming around a bend near a straightaway, Council crossed the center line and struck the group, Morrissey said. He called for help and immediately began CPR on one of the fallen cyclists, Morrissey said.
Daniel Brasse was 10 to 20 seconds behind his riding partners on Stevens Canyon Road. They had "gapped" him, he said, surging ahead on a slight descent.
Because Brasse said he hadn't been sleeping well since his daughter, Sophia, was born three weeks ago, the other three riders were fresher than him.
" 'I thank Sophia for you being here today,' " the 41-year-old Australian said his wife told him after the crash.
There was no sound to warn of what he'd find when he caught up to his friends. Instead, there were just screams of pain.
Brasse, a project manager with Genentech, said his First Aid training kicked in. He began trying to help Gough.
"She stopped breathing so many times," said Brasse, "Each time I told her, 'baby, keep breathing. You're strong.' "
Brasse was too focused on Gough to notice what else was going on. But Renshaw, who came up on the crash scene later, said that Council appeared to be in shock.
Kevin Valerio, who was riding with the group but pedaling behind Brasse, said Council seemed very disoriented at the crash scene. Another deputy on the scene was walking Council to her car, he said.
She also discourged Council from talking with the quickly gathering group.
"She said don't talk to those people, put her arm around him and took him to the car," Renshaw said.
Council's patrol car came to rest at the far side of the road, Valerio said, making it seem as though he completely crossed the oncoming traffic lane before smashing into the group.
Peterson died at the scene of the crash. He was on a cycling team sponsored by Roaring Mouse Cycles, a San Francisco bicycle shop. The shop's Web site posted word of his death on Sunday night.
Gough died several hours later after she was airlifted to Stanford University Hospital, Thibodeau said. Before and after she died, dozens of cyclists gathered at the hospital.
Friends on Sunday described Gough as a professional triathlete who recently took up cycling but immediately started winning Northern California races. The most recent was the Merco Credit Union Foothills Road Race in Merced County on March 2. Her team's captain called her "an Olympic hopeful" being scouted for the Summer Games in Beijing.
A 20-year-old man, identified by friends as Christopher Knapp of Germany, was seriously injured and was listed in stable condition Sunday night at Stanford University Hospital. A fourth rider was not hurt, Thibodeau said.
Reached by phone in his room at the hospital, Knapp declined to comment.
Morrissey described Council as "very emotional" about the crash. Afterward, he was sent home with an officer-in-crisis team, a group of peers who help a deputy deal with the traumatic after affects of such incidents, Morrissey said. The department offered counseling to the deputy.
Council started patrol after excelling at training, where he took lessons on handling a patrol car.
Morrissey called Council a "good young man with a strong moral and ethical background." Neighbors said Council's father, Toby Council, also worked with the Sheriff's department.
Sunday's accident rattled the whole sheriff's department, Morrissey said. Council is on paid administrative leave until the investigation is complete.
While fatal crashes are rare for the department, deputies often drive as many as 200 miles in a single shift, Morrissey said.
The last fatal crash involving a sheriff's patrol car happened in 1994, when a deputy trying to keep a suspect from running struck and killed the man near the intersection of West San Carlos Street and Bascom Avenue. The deputy was cleared of wrongdoing.
Just up the road from Sunday's crash, cyclist Jeffrey Steinwedel, 46, died in 1996 when a quarry driver struck him as he took a winter ride. The driver, Jon Nisby, was sentenced to a year in jail.
The CHP is asking anyone who witnessed Sunday's crash to call (408) 467-5354, extension 337.