Police arrested Mesa man Carlos Hillan for a murder-suicide plot. Detectives say they foiled his plan to kill his wife and her new boyfriend Tuesday evening.
Court documents list Hillan as suffering from depression, and during the booking process, Hillan was crying as officers took his picture for records.
A Phoenix father, Michael Sanders had a history of domestic violence, but he couldn't be stopped. Sanders murdered his wife and daughter at the home they once shared before turning the gun on himself.
Scottsdale Psychiatrist Michael Yasinski says domestic violence too often becomes deadly when there are underlying issues of depression, and the subject has no one else to turn to.
"These people tend to get hopeless," Yasinski said. "When someone gets hopeless or they have nothing to lose, no hope in the world, that's probably the one case where even a rational person can start to justify killing somebody."
Court documents list Hillan as being homeless and having jealousy issues. Couple that with his depression, and mental health experts like Yasinski says it can often turn a person with no history of violence into a potential killer.
Sanders had a similar story. According to a protection order his wife, Carol, filed against him last month, Sanders had become isolated:
"He doesn't have a definite job right now, has no friends and has estranged himself from his other family."
In both cases, Yasinski says isolation alongside severe depression can be considered a red flag.
"Without anyone to check and balance someone's thinking, it's easy for them to convince themselves that [violence] is the most reasonable and rational plan," Yasinski said.
Police say they caught Hillan in the act moments before he was to commit murder, but the justice system couldn't stop Sanders despite court orders requiring him to stay distant from his soon-to-be ex-wife.
In Arizona, a person can't be forced to get mental help, but Yasinski says others can identify the red flags of isolation and severe depression then take safety measures themselves before a potentially violent person reaches their boiling point.
For more on this story and other stories around Arizona from this author, follow Shawn Kline on Facebook and Twitter.
Copyright 2013 CBS 5 (KPHO Broadcasting Corporation). All rights reserved.