Virginia State Police late Friday identified the man who fatally shot a police officer on the campus of Virginia Tech on Thursday, then took his own life with the same gun, as a 22-year-old Spotsylvania County man.

They said the man, Ross Truett Ashley, was a part-time student at Radford University.

Virginia State Police spokeswoman Corinne Geller said police have found no prior connection between the gunmanand Virginia Tech police officer Deriek W. Crouse, 39, who was shot during a routine traffic stop shortly after 12:15 p.m.

Geller said police are “very confident” that the shooter acted alone. She said police believe he sought refuge in a campus greenhouse after Crouse was shot in a parking lot near Virginia Tech’s stadium, took off a “pullover top and a wool cap” and stowed them in a backpack, then left the backpack in the greenhouse.

Virginia Tech sophomore Shawn Ghuman live chatted with readers about Thursday’s shooting, giving a unique campus perspective. Read the chat transcript now.

Deriek Crouse (Virginia Tech )

He was next spotted by a Montgomery County, Va., sheriff’s deputy in the rear of a campus parking lot, Geller said. The deputy — one of scores of officers who had descended on the campus in response to the initial shooting — saw the man acting “furtively,” Geller said, and decided to approach him.

As the deputy drove across the parking lot, he lost sight of the man for a moment. When he reached the rear of the parking lot, Geller said, the man was prone on the ground, dead of a gunshot wound police believe was self-inflicted.

“At this point we have nothing to connect him to the Virginia Tech campus or school,” Geller said of the shooter. “We’re still piecing together who he is, his whereabouts leading up to the shooting. That’s all part of the investigation.”

Authorities said Crouse did not return fire when he was shot. Police have found no connection between the gunman and Crouse, Geller said.

The shootings on Thursday, and the chaos that followed, brought back horrifying memories of the 2007 massacre that claimed 33 lives and redefined how universities respond to emergencies. The shootings prompted a campus-wide lockdown that lasted four hours.

Crouse, 39, was from Christiansburg. A member of the force since 2007, he was married with five children and step-children. He also was an Army reservist who served in Iraq.

Police said he was on patrol in an unmarked Crown Victoria about 12:15 p.m. on Thursday, in the stadium parking lot, when he pulled over a Virginia Tech student driving a Silver Honda. While he was still in his vehicle, the shooter approached him and opened fire, police said. The shooter then ran. He was approached by the sheriff’s deputy in the second parking lot, about a half-mile away, at 12:45 p.m.

Footage from the video camera in Crouse’s unmarked police car show the gunman at the vehicle at the time of the shooting.

As state troopers fanned across the campus with automatic weapons after the shootings, thoughts across Virginia Tech immediately turned to April 2007, when the deadliest college shooting in U.S. history occurred.

“Today, tragedy again struck Virginia Tech,” said Charles W. Steger, president of Virginia Tech. “I can only say that words don’t describe our feelings, and they’re most elusive at this point in time.”

But as similar as the events seemed, the university’s response was far different.

Virginia Tech immediately went on lockdown, from the first alert at 12:36 p.m. to 4:30 p.m. Students and faculty huddled behind locked doors so that if a gunman was loose, he couldn’t enter campus buildings.

The episode provided the first real test of Virginia Tech’s vaunted emergency response system, created after the mass shooting by Seung Hui Cho, a disturbed English major from Fairfax County. University officials devised the system after intense criticism from victims’ families and independent investigators that they did not react quickly enough in 2007.

Thursday’s response — a barrage of text messages, e-mails, phone calls, classroom alerts and audible sirens across the 30,000-student campus — was nearly flawless, according to students, staff members and public officials.

“The plan played a very significant role in protecting all the students and the faculty and also to help facilitate a rapid and proper response by law enforcement officers,” Gov. Robert F. McDonnell (R) told reporters late Thursday.

The first campus-wide report of shots fired came at 12:36 p.m., minutes after the shooting, and advised of gunshots in the school’s coliseum parking lot, in a southern section of campus devoted to athletics. It told the community: “Stay inside. Secure doors.”

Alerts then came throughout the day. The second, at 12:47 p.m., described a suspect as “white male, gray sweat pants, gray hat w/neon green brim, maroon hoodie and backpack” and said he was heading “on foot towards McComas,” a facility that houses health and counseling services.

A third, at 1:11 p.m., said an officer had been shot. And so it went until the last alert, at 4:31 p.m., advising, “Resume normal activities.”

“The way the university staff is handling this . . . has been very comforting,” said Matt Banfield, a senior.

He was stranded, along with hundreds of fellow Hokies, inside the Squires Student Center for much of the afternoon. The students responded with a distinct calm, he said, tapping on cellphones and gathering information from television sets, the Internet, and social networks such as Twitter and Facebook.

Jermaine Holmes, director of academic support services for student athletes, sat in his office across from the coliseum parking lot and watched officers gather around the crime scene. “The facilities folks locked down the building immediately,” he said, speaking in the first minutes of the lockdown. “We’re not allowing any students or staff to leave.”

Freshman Matthew Spencer was walking toward a campus bus stop about 12:30 p.m. when he saw police and paramedics running toward the fallen officer. Then he got the alert from the university to get indoors. A short while later, “at least 15 police and undercover cars took off” toward where the second body was found.

Much of the campus was empty Thursday, save for the Newman Library. It was a reading day in preparation for final exams. Friday’s exams were postponed because of the incident. Inside the library, students were warned to stay clear of the windows.

The circumstances of this shooting bore no real comparison to Cho’s premeditated slaughter. But that was little consolation to the Virginia Tech community, still so scarred by the 2007 shooting that locals refer to it only as “4/16” — the date of the massacre.

“We all knew people, some of us personally, that got hurt on 4/16, so this isn’t a good feeling,” said Lee Hawkins, a 2008 Tech graduate who works for the university at Torgersen Hall.

This was another surreal afternoon. Police officers wearing flak jackets and carrying automatic weapons arrived about 2 p.m. to secure the building, known as Torg. Police shepherded students onto the “bridge,” a study area that links the building with Newman Library. Officers guarded entrances and allowed students to leave if they wanted, but “at our own risk,” Hawkins said.

The shooting happened, by chance, on a day when Virginia Tech officials were in Washington to appeal a $55,000 federal penalty from the Education Department over the university’s response to the 2007 shooting.

Virginia Tech officials were criticized for taking too long to lock down the campus after that shooting. There was a two-hour delay from the discovery of Cho’s first two victims to the first e-mail alert to campus. In between, 30 others were killed in an academic building that had not been locked.

Peter Read, the father of one of the 2007 victims, heard of Thursday’s shooting from a colleague at his office. He said he was immediately transported to that devastating moment when he learned of the death of his daughter Mary, a member of Annandale High School’s class of 2006.

Read took Thursday afternoon off from his job as a federal contractor. “It’s hard to think about anything else,” Read said. “It’s like deja vu all over again.”

Since the loss of his daughter, Read, 49, has been an outspoken proponent of gun-control laws and helped push for new safety measures for the campus where Mary, 19, an aspiring teacher, was killed.

By coincidence, he had spent Wednesday with other relatives in Washington, testifying before an administrative judge in the school’s appeal of the federal fine.

“Tech keeps saying they learned their lessons. . . . I really hope the leadership is doing the right things to protect the community, students, faculty and staff and the people of Blacksburg,” Read said. “They seem to be so far.”

As the sun rose over campus Friday, the police tape was gone from the crime scenes, and students resumed some of their normal routines. But many were still struggling to absorb the latest trauma to the university community.

“From the outside looking in, you can never understand it.” said freshman Sara Seeba, quoting a Facebook status message many students were posting as their own. “From the inside looking out, you can never explain it. Blacksburg is our home. This is our family.”

Staff writers Mark Berman, Emma Brown, Michael Alison Chandler, Annie Gowen, Tom Jackman, Jenna Johnson, Justin Jouvenal, Anita Kumar, Taylor Shapiro, Susan Svrluga, Clarence Williams and Debbi Wilgoren contributed to this report. Jouvenal reported from Blacksburg.