He has been charged with murdering 19-year-old Derrick Thompson, and his girlfriend, Alivia Welch, 18.

BBC: Maine shootings: Tenants killed in snow-shovelling row

In fact, her sister, Alivia Kropp, was the first person to spread the word and encourage her to speak out.

CNN: STORY HIGHLIGHTS

"It's very hard to see someone hurt and upset, and you want to do everything in your power to make sure they're not that way, " Alivia Kropp said.

CNN: STORY HIGHLIGHTS