PHOENIX, AZ — A man accused of killing his girlfriend in 2017 has been found guilty of second-degree murder.
The verdict agreed upon Monday was read in a Maricopa County courtroom on Tuesday morning.
Robert John Interval was tried on one count of premeditated first-degree murder in the presumed death of 34-year-old Christine Mustafa.
Jurors reportedly deliberated for two days after the seven-week trial. They found Interval not guilty of first-degree murder, but guilty of second-degree murder.
Mustafa was the subject of a 12-week search of a Phoenix landfill after disappearing in May 2017.
After the search ended in December 2017, police said there still was enough evidence to win a conviction.
During the trial, the prosecution said the 39-year-old Interval made incriminating statements in texts, bought mattress covers the day Mustafa disappeared in May 2017 and was seen outside a trash transfer facility later that day.
Police say Mustafa had plans to leave Interval.
"One day he will be free. I don't think it's fair that my sister, he didn't give her that option," said Mustafa's sister Linda Donaldson. "I think the closest to closure would've been first degree."
"To see this family suffer without her and they're all beautiful people and so loving and they say Christine was the loving one. It's such a shame she's not ever going to be here," added family friend, Diane Strand.
Interval faces up to 29 years in prison based on the conviction.