Erin Gagnon saw the Alexandria police officer drive up on his motorcycle — its red and blue lights flashing to warn motorists to move over. She heard the gunshot. She watched the officer’s head tilt back as he toppled to the ground.

By Gagnon’s and others’ accounts, Officer Peter Laboy had virtually no warning before he was shot and critically wounded Feb. 27. He had not drawn his weapon. According to prosecutors, he had not even fully climbed off his bike.

Those chilling details were among many spelled out at a preliminary hearing Wednesday for Kashif Bashir, a cabdriver accused of shooting Laboy in the middle of the afternoon near the heart of Alexandria. Although prosecutors did not spell out a motive — and declined to do so after the hearing was over — they detailed much of their evidence against Bashir, 27, as they persuaded Alexandria General District Court Judge Becky J. Moore to allow them to move the case forward.

Prosecutor Bryan Porter said he plans to seek a grand jury indictment May 20. “This hearing is the first step in holding the defendant accountable for his actions,” he said.

According to police, Laboy has been moved to a rehabilitation program. His wife posted on a blog detailing his progress that Tuesday was a “good day” and that her husband had been scheduled to see a neurosurgeon.

Alexandria officer Peter Laboy was shot in February. (Courtesy of Alexandria Police Department)

Bashir, dressed in green jail clothes, stared listlessly during the hearing and said nothing. His defense attorneys made no arguments on his behalf, though in their questioning of prosecutors’ witnesses they hinted that they might contest the analysis linking the gun found in Bashir’s cab to the bullet fragment found at the scene. They and Bashir’s relatives declined to comment.

Prosecutors, meanwhile, called nine witnesses to detail how a popular Alexandria officer known for his friendliness and dedication was shot and nearly killed.

Gagnon, a first-grade teacher at Lyles-Crouch Traditional Academy, testified that she was with students on the playground when she heard the shot and yelled for the children to run.

Paul Luong, a letter carrier who was in the area, said he, too, heard a pop, then saw a yellow cab driving down Wilkes Street.

Perhaps the most compelling testimony, though, came from Alexandria Officer Francis Powers, whose interaction with Bashir sparked a search for the cabdriver.

Powers testified that he was called to a shop in downtown Alexandria to deal with a “suspicious” person, and as he talked with a worker there, she suddenly yelled, “There he is!” Outside, Powers said, he saw a yellow van cab bearing the number 168 with a man inside.

Powers testified that he pointed repeatedly for the man to pull over, but “it was like he was looking right through me.” Eventually, Powers said, the man drove off, and Powers broadcast a description of the cab. As he rode around to look for it, Powers said, a letter carrier flagged him down and pointed him toward a fallen Laboy, who had been helping in the search.

“I could tell even before I got close to Laboy that he was very, very seriously injured,” Powers said.

Powers said he removed Laboy’s gun belt, which still was carrying his holstered weapon, so emergency workers could better provide care.

Other officers testified that they spotted and chased Bashir’s van, which prosecutors said reached speeds as high as 100 mph, until he crashed into a car in Fairfax County. They took him into custody and recovered several beer cans and a Sig Sauer semiautomatic handgun believed to have been used in the shooting, according to testimony.