The man accused of killing a married couple while they were on a hiking trip with their kids in Arkansas July 26 is being looked at for possible involvement in other murders.

Arkansas State Police allege Andrew James McGann killed Cristen Amanda Brink, 41, and Clinton David Brink, 43, while the couple was taking their children hiking at Devil’s Den State Park in Washington County, Arkansas. He pleaded not guilty during his arraignment on Thursday morning, according to 5 News.

Speaking outside of the courtroom, Washington County Prosecuting Attorney Brandon Carter said he’s still planning to seek the death penalty against McGann, adding it will be a long process.

Read more: foxnews.com