It is dangerous duty, requiring each motorcycle officer to overtake the motorcade at speeds up to 70 mph, slingshot ahead of it, then stop abruptly at an intersection before the caravan arrives.
The "motor jockey" holds traffic at the intersection until the last car rolls through, then speeds ahead to perform the maneuver again.
Sen. Hillary Rodham Clinton's motorcade met tragedy Friday when one of these motorcycle escorts, a Dallas police officer, was killed as he failed to negotiate a curve and slammed into a concrete guardrail.
It happened about 9:15 a.m. as the motorcade was headed across the Houston Street Viaduct toward a rally in Oak Cliff.
Senior Cpl. Victor Lozada was one of more than 30 motorcycle officers whose job it was to hold traffic at intersections while the black SUVs and patrol cars of the motorcade rolled through Dallas.
As the caravan headed south across the viaduct, Cpl. Lozada rounded a curve during his leapfrog toward the front. He apparently was unable to manage the turn.
Cpl. Lozada's motorcycle ran up onto a sidewalk lining the viaduct, its momentum forcing it against the concrete railing, according to sources with knowledge of the investigation. Then it slammed head-on into a concrete outcropping.
The 49-year-old catapulted dozens of feet forward along the roadway, the force of the crash knocking off his helmet.
Senior Cpl. Victor Lozada The motorcycle, driver and helmet lay on the road as the motorcade snaked around the wreckage. One of Cpl. Lozada's colleagues crouched over him, with his hand on the fallen officer's shoulder.
Mrs. Clinton saw it and asked to stop, according to a dignitary traveling with the campaigning presidential candidate's motorcade.
"They said that it would [slow] the ambulance getting to him, so they wouldn't allow us to stop," said Dallas County Commissioner John Wiley Price. "She was devastated. She wanted to visually see what had happened."
A squad car peeled off the motorcade to seal off traffic from the viaduct behind it. Meanwhile, Mrs. Clinton and Cpl. Lozada's fellow motorcycle officers pressed ahead without him.
While Mrs. Clinton greeted supporters in Oak Cliff, police officials sent officers to pick up Cpl. Lozada's wife, Theresa, from their Plano home. The officers also gathered the couple's children from school – two sons and two daughters ranging in age from 9 to 22.
Mrs. Lozada "was very strong," said one of those officers, Senior Cpl. Robert Garcia, a friend and former partner of Cpl. Lozada. "She told the children that their daddy would always love them and to remember him for what he was. She's just a good, strong-willed woman."
By the end of the rally, Mrs. Clinton got word that Cpl. Lozada was dead. She expressed regret for his family and fellow officers.
"I certainly am grateful for all they do for me, and more importantly, what they do for the citizens of cities like Dallas and others across our country," she told a small group of reporters and supporters.
Site of fatal crash The motorcade then shuttled her to Fort Worth, where she addressed a crowd of excited supporters only to say she was calling off the event because of the crash.
The motorcade then returned her to Dallas. She was whisked inside Methodist Dallas Medical Center, where Cpl. Lozada had been pronounced dead soon after his arrival.
Just outside the hospital's trauma unit, police officials stood about as Cpl. Lozada's family gathered in a visitation room.
Police Chief David Kunkle and Dallas Mayor Tom Leppert accompanied Cpl. Lozada's wife during the senator's 10- or 15-minute visit. Mrs. Lozada told the former first lady how proud her husband had been to escort her.
"What she talked about was that when he got ready to come to work today, that he wore a new uniform," Chief Kunkle said later. "He also recognized the importance of his role of ensuring that a very important person was safe and took a lot of pride in that."
Outside the hospital, several dozen of Cpl. Lozada's fellow motor jockeys parked their black-and-white motorcycles in formation. After the senator's visit, they filed inside the hospital, helmets in hand, to pay their own respects to the family.
At a news conference outside the hospital, Chief Kunkle spoke of the perils of being a motorcycle escort.
"The accident is still under investigation, but the motorcycle escorts we do are very dangerous," the chief said. "They require officers to speed up and ride ahead of the motorcade, and do that over and over again."
Late Friday, a motorcycle was set up in a memorial by the entrance to the Central Patrol station at 334 S. Hall St. Officers began surrounding it with cards, flowers and notes of farewell.
"He was a good guy; he was one of the very few good guys," said his friend, Cpl. Garcia.
Cpl. Lozada earned more than 135 commendations during his 20 years as a Dallas police officer, one of them as recently as a week ago.
In 1992, he and another officer earned a Life Saving Award for helping an 11-month-old baby who was choking on a small toy. As the baby began to turn blue, Cpl. Lozada held it upside down and swatted it on the back. He and the other officer were able to dislodge the toy and the baby breathed again.
Fellow officers say Cpl. Lozada was a devout family man who coached his son's soccer team and worked off-duty details at Target to earn money for his daughters' quinceañeras.
For many years, he served as a community policing officer, working especially to build ties between the department and Hispanic youth. He sometimes attended events in a "low rider" patrol car equipped with hydraulics.
"He would make it do all kind of crazy gyrations," Cpl. Garcia said. The car was uniquely successful at grabbing the attention of at-risk kids.
More recently he served as a traffic officer, driving a marked Chevy Camaro. A few months ago, an opening came up in the motorcycle unit, and he applied.
"I used to catch him in the hallway and tease him and say, 'Why would you want to go to motors?' " said Deputy Chief Tom Lawrence, commander of the traffic unit. "He said, 'It's something that I've always wanted to do.' "
Cpl. Lozada had the job for a little over a month before Friday's crash.
"He was real happy," Cpl. Garcia said. "He was just doing what he wanted to do."
