FARMINGTON — Law officers throughout the county are on high alert after three recent incidents where armed suspects turned their weapons on law enforcement.

The incidents happened in Farmington, Aztec and Ojo Amarillo. The crimes have little in common other than the fact that police were threatened with violence.

"There is a sense of alertness for every law enforcement officer throughout the county," said Lt. Shane Ferrari, the commander of the San Juan County SWAT team, which responded to two of the recent incidents. "When it hits this close to home, it causes all of us to think. We need to be alert and not be complacent."

Mark Chavez, 49, was fatally shot by a Farmington police officer during an altercation outside a Farmington home on Tuesday. Chavez had a blunt object -- police would not provide further details on the weapon involved -- and moved aggressively at Sgt. Shawn Scott who shot and killed Chavez.

The incident started when Chavez called police and told them he had just killed a woman. Police haven't found any evidence to support the claim, Farmington police Lt. Taft Tracy said.

Another suspect, Byron Boyd, 39, shot and killed himself after he barricaded himself in a cement building at a home near Aztec on Dec. 24.

Boyd was wanted for questioning in a string of recent burglaries and check fraud crimes. He had cut off his ankle monitor and was hiding out at a friend's house when police found him.

The sheriff's office said Boyd shot at deputies several times before he turned his gun on himself.

A third suspect, Harold Pete, 29, was taken into custody early Monday morning after a five-hour standoff where Pete took children hostage inside a home in Ojo Amarillo, a Navajo reservation town south of Kirtland.

FBI agents, Navajo police and Farmington and San Juan County SWAT teams surrounded the house for hours and negotiated with Pete through the night. He released the children one by one before he surrendered.

Pete was charged with assault with a dangerous weapon, use of a firearm in the commission of a violent crime and aggravated burglary.

Pete never fired shots at police during the standoff. But officers saw him using his shotgun to break windows of the home and he told hostage negotiators during the standoff that he wanted to get into a shootout with police, according to court documents.

Police have several theories -- from holiday stress to increased alcohol use -- to explain the recent increase in violence aimed at law enforcement.

"We tell our guys to be extra cautious because I feel there's a heightened risk this time of year," Tracy said.

Other than a deputy who was hospitalized with hypothermia after the hours-long standoff on Christmas Eve, no officers have been hurt during these cases.

While police say they will be on the lookout for violence directed at them, they are hoping the recent violence was just a coincidence.

"It definitely is something that is not of the norm. We don't know if it's just a fluke that we got these three incidents close together or if its going to be a sign of times," Ferrari said. "I'm hoping it's just a coincidence."