CAMDENTON, Mo. -- It's been five years since Mark Gerber has seen his brother and nephew.
"First of all it doesn't seem real. Five years is a long time," Gerber said.
Gerber's brother, Chad, was found dead at his Laclede County home from a gunshot wound to the head.
Chad's son, 15-year-old Riley Gerber, was also shot in the head. He was taken to the hospital and died four days later.
Matthew Rumbaugh was arrested and charged with the murder of both Chad and Riley.
Deputies said Rumbaugh shot the two Gerbers because he was having an affair with Gerber's wife, and was tired of waiting for her to leave him. They say he broke into the home and killed them.
"For me, personally, there were times when I didn't feel this day was going to come," Gerber said.
A long legal battle, and a change in venue delayed the trial, which officially started today with opening arguments.
"Kind of ripping a band aid off," Gerber said. "When it takes this long, some of those wounds we hope started to heal a little bit. I'm certain over the next few days, it's just going to make it fresh again."
Chad and Riley were shot on Chad's birthday, July 8.
Monday will be the first day the jury will hear and see evidence in the case against the man charged in their deaths.
Monday is what would have been Riley's 20th birthday.
"I'm not a really superstitious person, so I'm going to call it an interesting coincidence, but I'm hoping it means the odds are in our favor," Gerber said.