Motive: Something that causes a person to act in a certain way, do a certain thing, etc.; incentive.

Despite all the science, no one really knows the human brain as the actual workings of a person’s mind is in a world of its own.
Police are still trying to figure out the reasoning behind a couple of seemingly random shootings in the last two days, one in Nevada, the other across the country in West Virginia — 11 people dead in all.
Life nowadays might be a bit much for some people, but using high-powered weapons to figure your personal problems is not a solution.

(Illustration found here).

Duh!

In Carson City, Nev., a 32-year-old guy by the name of Eduardo Sencion walked into the IHOP there and on a beeline, went shooting his way through the restaurant to a table in back where five National Guardsmen were eating breakfast: He hit all five Guard members, killing three of them, and killed another woman and wounded five other people before taking his own life.
The Carson City sheriff said right now there’s no motive for the shooting, although, it appears Sencion was out for the Guardsmen:

“It appears as though his gunfire was primarily focused on those military members,” Sheriff Furlong said. “We do not know whether or not the gunman was aware that there were National Guardsmen in the restaurant, but it appears as though he did.
He had to travel through the entire restaurant to get to the back where the Guardsmen were having breakfast.”

A nearby shop owner, who from all indications had access to a firearm himself, gave this account:

Ralph Swagler, the owner of a nearby barbecue restaurant, told The A.P. that he saw the gunman pull up outside the restaurant, where he first shot a man on a motorcycle and then headed inside.
“I wish I had shot at him, but he was going in the IHOP,” Mr. Swagler said.
“But when he came at me — when somebody is pointing an automatic weapon at you, you can’t believe the firepower, the kind of rounds coming out of that weapon.”

Sencion was packing an AK-47.

Meanwhile, in West Virginia, another guy, 22-year-old Shayne Riggleman, went on a rampage, killing five people apparently semi-random before taking his own life.
When found, he had a a high-powered rifle, a second rifle and a .22-caliber handgun.
Police reported Riggleman shot and killed five people at a home in West Virginia, one female victim six months pregnant, left there and ran down an elderly woman in neighboring Pennsylvania, then also shot and wounded a gas station attendant as he crossed back through West Virginia.
He then took his own life in Kentucky.

Authorities have no motive, and do not yet understand the connection between Riggleman and the victims.
After the shootings, Riggleman was pulled over in Kentucky for reckless driving, but shot himself before police could get to him.
West Virginia State Police Capt. James Merrill said “one of the most heinous crimes I’ve ever witnessed,” adding, “It’s unfortunate it ended the way it did… but I do not believe that he would’ve stopped.”

Some clues might come from social media:

Authorities searched Riggleman’s Morgantown apartment and were studying his Facebook page.
Riggleman apparently lived alone, and police did not immediately know whether he was employed.
He does have a criminal history but Merrill declined to elaborate, saying only that “he was known by law enforcement.”
On a public Facebook page for a Shayne Franklin Samuel Riggleman, a string of Wall Posts from the past week seem to hint at a troubled relationship.
“There is a direct corelation between the amount of love you have for someone and how crazy you go when you lose them,” reads one.
“I mate for life, not like a penguin though,” reads another. “I mate for life like a praying mantis.”
And one, ominously, says only, “We’re not promised tomorrow.”
Riggleman’s profile page, meanwhile, contained several quotes.
At the top of the list, unattributed, was this one: “I ain’t goin’ out without a fight. I’m with whatever. it WILL be YOUR LIFE before MY LIFE.”

Another couple of weird, ugly news from the nowadays.

The dad of one of Riggleman’s victims said this:

Charles Richardson Jr., whose son was among the five shooting victims, told The Associated Press he didn’t recognize Riggleman’s name or know his connection to the family. Nor was he aware of his son having trouble with anyone.
Richardson said his son worked for FedEx and liked to tinker on vehicles and computers. The two were not close, he said, even though the elder Richardson lives in a mobile home within sight of his son’s house.
“He went about his business and I went about mine,” he said, “but I loved my son.”

As a parent, that was so freakin’ sad — now the boy’s gone, without reason, without  incentive.