These Are the Deadliest Mass Shootings of 2018

Twelve people are dead in California in the latest mass shooting to rock the country in 2018. Ian Long, a 28-year-old Marine veteran, opened fire inside a Ventura County country bar jammed with line dancing college students, authorities said.

Long first lobbed in smoke grenades, then began shooting, witnesses said. He said nothing as he calmly fired, killing a sheriff's sergeant responding to the chaos and 11 others before turning his gun on himself.

Investigators were trying to determine a motive. 

These are the deadliest mass shooting thus far this year.

17 Students and Staff Killed at Marjory Stoneman Douglas High School on February 14 

Former student Nikolas Cruz, 19, allegedly opened fire at the Parkland, Florida, campus in what has become known as the deadliest high school shooting in U.S. history, surpassing the Columbine High School massacre in 1999. An assistant football coach shielding two students died at the scene. Senior Meadow Pollack was shot four times and died as she crawled toward a classroom door. 

Seventeen others were injured in the shooting. Outraged survivors became national spokespersons for tougher gun laws, demanding more protection for children and students. They led a massive march on the nation's Capitol, pleading for an end to gun violence.

11 Worshipers Killed at Tree of Life Ceremony in Pittsburgh on October 27

Robert Gregory Bowers, 46, allegedly shouted "All Jews must die!" as he stormed a Pennsylvania synagogue during Shabbat morning services. He was armed with an AR-15 assault weapon and three Glock hand guns, authorities said, as he made his way through different rooms of the house of worship.

Among the dead were two brothers, Cecil and David, aged 59 and 49, and Bernice Simon, 84, and her 86-year-old husband, Sylvan. Rose Mallinger, 97, also was killed. Four police officers were injured, three of them shot and one hurt by shattering glass.

The suspect, wounded by police, was transported to a nearby hospital where his medical team included three Jews.

8 Students and 2 Teachers Shot to Death at Santa Fe High School in Texas on May 18

A 17-year-old student at the Houston-area school, Dimitios Pagourtzis, was identified by authorities as the shooter in a rampage that wounded 13. He began shooting in an art class, telling one classmate, "I'm going to kill you," authorities said. Some students barricaded themselves in a storage closet and one was killed after the gunman shot through the doors, witnesses said.

Other students reported hearing Pagourtzis shouting "Whoo hoo!" and "Are you dead?" as he fired. The teen was reportedly upset by a female student who rebuffed his repeated advances and once confronted him in front of a classroom. The girl was among the dead, authorities said. 

Texas Gov. Greg Abbott called the shooting "one of the most heinous attacks that we've ever seen in the history of Texas schools."

Five Killed in Shooting Spree Across Bakersfield, California, on September 13

In less than 40 minutes, and across three locations, a gunman identified as Javier Casarez, 54, shot his estranged wife and four others before turning the gun on himself, authorities said.

Police said the shootings were a part of a domestic violence incident. Petra Maribel Bolanos de Casarez was shot and killed, along with Manuel Contreras, 50, at a trucking company. Casarez then chased 50-year-old Antonio Valdez from that location and shot him to death in front of a sporting goods store, authorities said. 

At another residence, he fatally shot Eliseo Garcia, 57, and his daughter, Laura, 32. In a confrontation with police, Casarez shot himself in the chest and died.

Five Killed at The Capital Newspaper in Maryland on June 28

Gunman Jarrod Ramos allegedly started shooting at the The Capital's offices in Annapolis, eventually killing five employees, many of them running for cover. The local paper had previously published an article about Ramos being sentenced to probation after using social media and email to harass a former high school acquaintance.

Angered over the story, Ramos had filed a lawsuit against the paper, but it was dismissed in court. He allegedly sent threatening letters to the paper, but no legal action was taken over them, police said. Ramos barricaded the paper's rear door, trapping the employees inside, authorities said. 

He was armed with a double-barreled shotgun, police reported. The dead included Gerald Fischman, 61, editorial page editor, Rob Hiaasen, 59, assistant editor and weekend columnist, and Wendi Winters, 65, a community beat reporter. 

Ramos is currently in jail awaiting trial, charged with five counts of first-degree murder, six counts of first-degree assault and 11 counts of using a firearm in the commission of a felony.

There were eight other shootings this year in which five people were killed and nine incidents in which four people died.

The non-profit Gun Violence Archive estimates more than 500 people have been killed in multiple shootings this year.

There are seven weeks left in 2018.