Karen DeSha clutched the bench in front of her and began to shake, letting out short yelps as the man in shackles and an orange jumpsuit shuffled into the Prince George’s County courtroom. DeSha had driven eight hours for this, her first face-to-face encounter with the man accused of killing her son. She left, sobbing, after only a few minutes.

In January, 16 people were slain in Prince George’s County, the most in any single month this year. The sudden and inexplicable string of mayhem set the county on a course for an increase in homicides as compared with 2010. Although every other type of crime decreased this year, the homicide victims’ families, including DeSha’s, stand as a sobering reminder that Prince George’s is still touched by serious violence.

Police have made arrests in six of the January homicides (in a seventh, the killing was deemed to be justified). In three of the cases, suspects have been convicted and sentenced. Three other cases are working their way through the court system.

The killing of Justin DeSha-Overcash is one of those.

The 22-year-old University of Maryland student was fatally shot in what police say was a botched robbery. Stephan Weaver, 23, pleaded guilty to attempted robbery and related charges and is awaiting sentencing. The alleged gunman, 24-year-old Deandre Williams, is fighting murder and robbery charges.

DeSha, Justin DeSha-Overcash’s mother, traveled from her home in Asheville, N.C., to see Williams in court in December. She carried a photo album of her son and pinned two school portraits of him to her shawl. Behind the portraits, she tucked a golden lock of his hair.

DeSha had come to a similar hearing for Weaver in October. In ways, though, that was easier. Weaver drove Williams to DeSha-Overcash’s College Park house Jan. 11, police say, after hearing that DeSha-Overcash carried lots of drugs and money. So they set out to rob him, police say.

But Weaver, police have said, never went inside; he found out that DeSha-Overcash had been shot when Williams came outside and told him.

DeSha-Overcash’s family and friends have long disputed that he was a drug dealer; at one time, DeSha even protested outside Prince George’s County police headquarters over the issue. DeSha said she sometimes wished that police had never closed her son’s case because it sullied his reputation. DeSha-Overcash, she said, was a double major in physics and astronomy at U-Md. who wrote music and worked in the campus observatory. He was “caring, funny and compassionate,” she said.

“I know nobody believes me about the drug dealer stuff,” DeSha said, “but my son was not a drug dealer.”

Since her son’s death, DeSha, 56, has seen a therapist regularly and been in and out of the hospital for treatment of depression. She joined Parents of Murdered Children — which she calls “a club no one wants to be a part of” — and talks regularly with a woman whose teenage daughter was killed in Prince George’s in 2005.

None of it, DeSha said, seems to help.

A former high-end real estate broker, DeSha said she has not been able to return to work. Most of her time, she said, she sleeps. When she feels up to it, she posts memories about her son on her Facebook page, some of them copied from letters she wrote about her son when he was alive.

“I just want my son back,” DeSha said, “and it’s never going to happen.”

DeSha’s ex-husband, Randy Overcash, and several of her son’s friends accompanied her to court this month. Overcash, Justin’s father, said that for months after his son’s death, he would go outside in the wee hours of the morning to stare at the stars. It was his way of talking to his dead son, he said.

“You just kind of don’t know how to take that step to get started back,” Overcash said.

Soon, though, Overcash, 56, of Warminster, Pa., said he thought that his son “wouldn’t like the way I was handling this.” He called a friend, who got him a job managing sales for a window manufacturer. As far as grieving goes, he said, it was the “best thing that happened to me.”

“I couldn’t live the way Karen lives,” Overcash said. “I have to try to gravitate toward peace and harmony and try not to let my emotions show.”

As DeSha rushed out of the courtroom, Overcash crossed his legs and wiped his brow, his face red. When his ex-wife returned several minutes later, he moved over on the bench. Both stared intently at the man police say killed their son.

They listened as Williams’s attorney pushed to have his client’s confession thrown out, arguing that Prince George’s detectives violated Williams’s Miranda rights and induced him to talk on the vague promise of leniency. A county Circuit Court judge rejected the arguments. Williams’s attorney and his family declined to comment afterward.

As of Tuesday evening, Prince George’s had had 107 homicides in 2011, compared with 98 for all of last year. That includes 11 cases deemed justified, such as instances in which police officers fatally shoot a dangerous person. Top commanders say that January — a statistical anomaly — is largely to blame for the increase.

For Overcash and DeSha, the figure is more personal.

Thinking about the year’s homicide victims gives Overcash a “sickening” feeling and makes him wish he could “just pick Justin out” of the group. DeSha said that part of her died Jan. 11 because life without her son is hardly a life at all.

“I lost my optimism. I lost my funny. I lost my trusting people,” DeSha said. “Another Karen will come along one day. But that Karen is gone.”