Even as friends and family still were coming to grips with the shocking death of 18-year-old Bianca Roberson, those acquainted with the man accused of her road-rage slaying say they were taken aback by the horrific allegations against someone they knew as "even-keeled."

"I never saw him as a hothead or in any way a threat to anyone," said Greg Parker, who worked with David Desper, 28, of Trainer, Delaware County, as a water-well contractor for a few years. He said the alleged actions would be "very uncharacteristic" of Desper, who remained jailed without bail on Monday on murder charges. He had no previous serious offenses, according to court records, just a few traffic violations for driving unregistered vehicles without proper inspection. In 2007 he was accused of drag racing in Philadelphia but was found not guilty, the records showed.

Desper is accused of shooting and killing Roberson at the height of the homebound commute on Wednesday along a stretch of the Route 100 bypass in West Goshen Township where the highway funnels into one lane.

The victim's friends, meanwhile, continued to mourn her death, and members of her family had asked for privacy.

On Monday, Diana Williamson, 18, of Brookhaven, who worked with Roberson at the White Horse Village retirement community, recounted what happened when she and her colleagues heard the news of the arrest.

Before their 11 a.m. shift. Sunday, a dozen White Horse dining-room employees huddled around 19-year-old Sydney Miller's cellphone, watching a live feed of the news conference. When it was announced that authorities had arrested Desper, a supervisor yelled, "Yes!"

"Everyone was so happy. Some of us started crying," Williamson said. "It was just a 'Thank God he is off the streets, and can't do this again.' "

Williamson said her first thought when she saw Desper's mug shot was "could this have been a racial thing?"

Chester County District Attorney Tom Hogan said Sunday that there was "no indication that we're aware of that this was a race crime or a hate crime."

Parker said his friend Desper was a people person who was "not in any way a racist, or nasty person, or threatening, or on drugs."

In Facebook posts and comment threads, Desper's friends described him as a calm and level-headed person who rarely seemed to get angry.

Karl Pritz, 30, of Bensalem, said he and Desper were tuning up a Camaro a few weeks ago when a window flew off the car as it was driving. Pritz said Desper remained completely calm and even joked about the misfortune, driving around Chester at night to try to find the window.

"Was a cool, calm guy," Pritz said. "Not on edge or snap personality. Seemed even keel even when he had something go wrong that cost him money. … He just shrugged it off and kept going."

If the allegations turn out to to be true, "Everyone that knows Dave is very disappointed in his actions, and we just want to know what led him to commit such an act," said Parker, 30, of Aston. "Because if you knew Dave, then you knew this wasn't like him."

Attempts to reach Desper's family were unsuccessful Monday, and his lawyer, Dan McGarrigle, declined to comment.

Desper surrendered at McGarrigle's office in Media around 2 a.m. Sunday. Shortly afterward, police hauled in his red pickup truck, which was found parked on Huntingdon Farm Drive in Glen Mills.

Bianca's father, Rodney Roberson, said last week that his daughter was driving home from a shopping trip in Exton when the confrontation occurred.

Roberson's green 2009 Chevrolet Malibu was trying to merge into the lane along with Desper's red Chevrolet Silverado pickup truck, police said. After Desper shot Roberson in the head, her car veered off the road and into a tree. Desper, meanwhile, sped off toward Delaware County.

In a search of Desper's home, police said, they found a .40-caliber Smith & Wesson semiautomatic handgun and .40-caliber ammunition, the same caliber weapon and ammo used in the shooting. Desper had purchased the gun legally three years ago, Hogan said, and had a license to carry it.

Desper's charges include first- and third-degree murder, possession of an instrument of crime, and reckless endangerment.

Williamson said she had one question about Desper's alleged behavior: "Why? No one had to lose their life over something so simple."

Williamson said she plans to get a tattoo of Roberson's signature on her rib cage as soon as possible to pay tribute to her friend.

Williamson said her close-knit friend group will never be the same without Roberson, a recent graduate of Bayard Rustin High School who was heading to Jacksonville University in the fall.

But, Williamson said, Desper's quick arrest brought her some closure.

Over the last few days, Williamson said she has become a more cautious driver, constantly thinking about what happened to her friend on a routine drive home from a shopping trip.

"If someone looks like they're starting something with me," Williamson said, "I back off anymore."