Last year, 64 officers died in the line of duty.
The decade's highest total came in 2011, with 73 officers killed.
Clayton, 42, was shot and killed
when she tried to confront a murder suspect in the parking lot of a local Walmart in Florida on January 9.
When police arrived on the scene they found the 17-year veteran dead from gunshot wounds. Officers could not revive her after performing CPR.
The Orange County Sheriff's Office launched a manhunt
that eventually led to the capture of Clayton's suspected shooter -- Markeith Loyd.
Loyd had been on the run from authorities for nearly a month. He was wanted in connection to the fatal shooting of Sade Dixon, 24, his pregnant ex- girlfriend outside her home in the Pine Hills neighborhood on December 13, 2016, CNN affiliate WFTV
Loyd, 41, has been charged with two counts of murder in the deaths of Dixon and Clayton, said Orange County Sheriff Jerry Demings. He also faces charges of attempted murder and aggravated assault for injuries Dixon's family member sustained in the alleged encounter.
Clayton's death marks the first fatal shooting of a police officer in the US this year, according to the memorial fund
Clayton was married and the mother of a college-age son. She was promoted posthumously to lieutenant at her funeral.
DEPUTY OFFICER NORMAN LEWIS
Lewis, a deputy first class with the Orange County Sheriff's Office, was killed
in a vehicle accident while searching for Clayton's gunman.
Lewis, 34, was driving a motorcycle when another vehicle turned in front of him. He died in the crash a couple hours after Clayton was shot.
The 11-year veteran in the sheriff's department, mostly worked in the traffic division. The University of Central Florida graduate played in the offensive line on the school's football team from 2000-2003 and earned his degree in criminal justice in 2004, CNN affiliate WFTV reported.
DEPUTY SHERIFF COLT ALLERY
Allery, 29, of the Rolette County Sheriff's Office, was fatally shot during a pursuit of a stolen vehicle on Wednesday. The suspect was killed and another officer was wounded in the incident, according to the memorial fund. Allery is the first officer killed in North Dakota this year, the fund said.
DETECTIVE JERRY WALKER
Walker, 48, was shot and killed
while responding to a 911 call about an armed man outside a home in the Dallas suburb of Little Elm on Tuesday. A standoff ensued. The suspect opened fire from inside the home striking Walker. The suspect was found dead in the home hours later.
Walker was transported by helicopter to a local hospital where he later died from his injuries, police said.
Walker leaves behind a wife and four children, the youngest just a few months old. The oldest is 22 years old.