The Fort Hood shooting looks to dominate Sunday morning talk show news, with guests discussing the second mass shooting in five years on the Texas base. 

Four people, including the gunman, were killed in Wednesday's rampage, which left 16 people injured and plenty of unanswered questions. Reports emerging Saturday suggested a simple dispute over paperwork sparked the shooting spree, which ended with Spc. Ivan Lopez, 34, taking his own life.

“At this time, we have not established a concrete motive but we will do everything in our power to do so,” Chris Grey, a spokesperson for the U.S. Army Criminal Investigation Command told reporters Friday. “Given that the alleged shooter is deceased, the possibility does exist that we may never know exactly why the alleged shooter did what he did.”

Newsmakers will likely delve into issues such as gun control, mental health and base security in the wake of the shooting.

Here are the Sunday lineups: 

ABC's “This Week,” will feature Rep. John Carter, (R-Texas), whose congressional district includes part of Fort Hood and former Gen. Peter Chiarelli, a retired Army vice chief of staff, who oversaw suicide prevention efforts.

NBC's "Meet the Press” will sit down with retired Adm. Michael Mullen, former chairman of the Joint Chiefs of Staff to discuss what the latest shooting reveals about the mental health needs for U.S. soldiers and if the military is providing enough support. 

Also scheduled to appear is Shaun McCutcheon, whose legal challenge of decades old campaign finance restrictions proved successful in a high-profile Supreme Court case decided earlier in the week. Robert Weissman, president of Public Citizen, a consumer advocacy group, is likely to give the opposing perspective. 

CBS' "Face the Nation" will focus on Fort Hood's latest developments with chairman of the House Homeland Security Committee, Rep. Michael McCaul, (R-Texas) about what authorities have learned regarding a possible motive and what can be done to prevent tragedies like this in the future. White House senior adviser Dan Pfeiffer will join the newscast later to tout ObamaCare's enrollment milestone of 7.1 million sign-ups in healthcare exchanges.

CNN's "State of the Union" will look at Fort Hood through the lens of mental health, with Rep. Tulsi GabbardTulsi GabbardElection Countdown: Takeaways from heated Florida governor's debate | DNC chief pushes back on 'blue wave' talk | Manchin faces progressive backlash | Trump heads to Houston rally | Obama in Las Vegas | Signs of huge midterm turnout Gabbard considering 2020 run: report The importance of advancing the U.S.-India partnership MORE, D-Hawaii, and Rep. Tim Murphy, R-Pa. The show will also discuss the latest on the search for the missing Malaysia Airlines jet.