King County experienced the fewest homicides — 59 — in a decade last year, as suicides declined after a spike in 2009.

The information comes from the King County Medical Examiner’s Office. In the agency’s annual report, officials analyze suspicious, sudden, unexpected and violent deaths in King County, plus trends in drug overdose deaths, homicides and traffic fatalities. The agency released the 2010 report Monday.

Overall, King County experienced fewer homicides, suicides, accidental deaths and deaths from natural causes last year than in 2009. (The report includes only deaths under medical examiner’s office jurisdiction.)

The deaths investigated by the medical examiner’s office also made 156 organ transplants possible last year.

Firearms ranked as the most frequent instrument of death in homicides and suicides.

Though drug overdoses declined from 2009 to 2010, overdoses still caused more than one-third of all accidental deaths investigated by the agency. Officials also recorded a substantial decrease in methadone- and oxycodone-related deaths from 2009 to 2010.

Investigators said methadone contributed to 77 deaths last year, compared to 129 in 2009. The drug ranked as the primary cause of death in 67 deaths from last year, compared to 85 in 2009. Oxycodone contributed to 77 deaths last year, compared to 105 in 2009.

Following a decline from 2008 to 2009, traffic deaths increased last year to 150 from 141 during the previous year.

“Understanding how and why people died in King County allows us to target our public health efforts to prevent early deaths,” Dr. David Fleming, Public Health – Seattle & King County director and health officer, said in a statement. “Take traffic fatalities, for example. We know that alcohol and drug impairment, speed and not wearing seatbelts contribute to traffic fatalities. So we work with partners throughout King County to help alleviate those causes and hopefully save lives.”

The annual report from the King County Medical Examiner’s Office offers detailed analysis of suspicious, sudden, unexpected and violent deaths, plus trends in drug overdose deaths, homicides and traffic fatalities. The agency released the initial data from the 2009 report Dec. 28.

The medical examiner’s office estimated 12,967 deaths occurred in King County in 2009. Officials performed autopsies in about 10 percent of the cases — or 1,226 deaths.

The agency assumed jurisdiction in 2,190 deaths — 989 natural deaths, 632 accidental deaths, 253 suicides, 141 traffic deaths, 63 homicides and 59 deaths due to undetermined causes.

The 2009 total includes one Newcastle death, which was due to undetermined causes. The medical examiner’s office has responded to one death in Newcastle per year since 2006. It responded to suicides in 2006 and 2008, and an accidental death in 2007.

The medical examiner’s office identified firearms as the most frequent instrument of death in homicides and suicides. The office recorded 146 firearm deaths in 2009, including 41 homicides, 100 suicides and one accidental death.

The most common cause of accidental death: falls. The medical examiner’s office said most of the accidental deaths due to falls involved people age 70 and older.

“Medical examiner death reviews are a critical component of public health prevention efforts,” Dr. David Fleming, Public Health – Seattle & King County director and health officer, said in a statement.

Officials then use the data from the report to launch programs, such as crisis counseling, to safeguard residents.

“Because we know the circumstances, risk factors and trends of death in King County, we can target efforts and work to prevent early deaths,” Fleming said. “Traffic fatalities are a clear example of this. We know that alcohol and drug impairment, speed, and failure to wear seatbelts contribute to traffic fatalities, and we work with partners throughout King County to help alleviate those causes.”

The agency also had to confront cuts to public health services. The medical examiner’s office has eliminated 4.5 full-time death investigators, plus the reduction of a part-time anthropologist, since 2009. The reduced number of staff has led to fewer investigators on the night shift and longer response times.

“Our hearts go out to the friends and families who have suffered losses,” Dr. Richard Harruff, chief medical examiner, said in a statement. “Every death we review receives our fullest respect and attention. We work to investigate and resolve the manner and cause of death as quickly as possible, and in the most scientific and professional manner so grieving loved ones can find some solace.”