Rahul Gupta (Dan Morse/The Washington Post)

Rahul Gupta, a onetime aspiring biomedical engineer, was sentenced to life in prison Wednesday after an emotional hearing in Montgomery County that shed light on a person often overlooked during the high-profile trial this year: the close friend he killed.

Mark Waugh died after being stabbed and slashed 11 times inside a high-rise apartment in Silver Spring.

“I loved him more than life itself,” Waugh’s mother, Nancy, said in court, listing big reasons — her son’s happy demeanor, his closeness with his three brothers, his commitment to his friends — and smaller ones.

“I miss his smile,” Nancy Waugh said, “and his hugs and just the way he tilted his head.”

Mark Waugh was an Eagle Scout and was credited in 2007 with saving the life of a fellow student who was choking on a bottle cap. He graduated with honors from James Madison University in Harrisonburg, Va., and spent a year in South Korea teaching debate tactics to other students before going to law school at Georgetown University. He was 23 when he was killed.

Mark Waugh (Courtesy of Waugh family)

One of many aspects of the case that were difficult for his family were the actions taken by Gupta after the killing. He initially told police he attacked Waugh because he caught Waugh cheating with his girlfriend. Gupta, now 25, recanted that claim in court, but by then it had been widely reported.

“He killed my son and then tried to damage his reputation,” Waugh’s father, Bill, said in court.

In the hours before the killing, Gupta and Taylor Gould, his girlfriend at the time, went out in the District for dinner and drinks to celebrate Gupta’s birthday. They were joined by Waugh, a friend of Gupta’s from Langley High School in McLean, Va., and they all ended up back at the Silver Spring high-rise apartment where Gupta and Gould lived.

About 3:30 a.m., Gould called police to the apartment, where they found Waugh dead on the floor next to Gupta and a large knife.

Both men were covered in blood.

According to authorities, one of the officers had the following exchange with Gupta:

Former George Washington University grad student Rahul Gupta, was sentenced to life in prison Wednesday for the 2013 fatal stabbing of his friend Mark Waugh inside a high-rise apartment in Silver Spring. (WUSA9)

“What happened?” the officer asked.

“My girlfriend and my buddy were cheating,” Gupta said. “I walked in on my girlfriend and my buddy cheating. I killed my buddy.”

The officers took Gupta into custody. He would later change his story, saying that he had confessed to the crime to protect Gould and that the cheating claim was part of that narrative. In truth, Gupta went on to claim, it was Gould who had killed Waugh.

That set the stage for Gupta’s March trial, where Gould testified that she had no clear memory of the events at the apartment that night because she had had a lot to drink. That allowed Gupta to testify that while his memory of the night was not altogether clear — in part, he said, because he tripped in the apartment and hit his head on the floor — it was Gould who attacked his friend.

“I knew that she had hurt him somehow,” Gupta testified.

But the jury did not believe his testimony and found him guilty of first-degree murder after deliberating for less than five hours. No clear reason was given for Gupta’s attack on his friend.

At Gupta’s sentencing Wednesday, Bill Waugh told Montgomery Circuit Judge Richard E. Jordan that he constantly remembers what a medical examiner said from the witness stand during Gupta’s trial.

“When I wake up in the morning, there is an instant of peace. And then the same words come across my mind over and over again: ‘He lived for several minutes after the attack,’ ” Waugh said of his son. “I cannot imagine what he thought during that period of time.”

The father spoke about the devastation to his family, using the term “poverty” to describe the loss and the other damage that Gupta’s crime had done to the members of the family.

“This is a poverty of hope, of sadness, of longing,” he said. “He has put us someplace we cannot get out of, ever.”

Gupta also spoke. He did not admit to the crime. Speaking in an almost clinical tone, he told the judge that Mark Waugh had been a great person.

“Mark was endowed with many God-given talents — his piercing wit, his infectious alacrity and his dazzling oratory prowess, to name just a few,” Gupta said.

Jordan had the last word. He said he was convinced that Gupta had killed Waugh. He said he was stunned that Gupta chose to speak about Waugh in such a way during the sentencing hearing — suggesting it was part of constant efforts by Gupta to rewrite what had happened.

“It appears to be more deflection and a continuation of the narrative and of the lie,” Jordan said. “I don’t hear regret.”