SAN DIEGO --
A man suspected of fatally wounding a San Diego officer in an unprovoked attack left a suicide note at his apartment before he was cornered, gun in hand, and shot to death by police, officials say.
Officer Jeremy Henwood, a four-year veteran of the department, died at a hospital Sunday, a day after he was shot in the face as he sat alone in his patrol car.
"I could tell you that this was a senseless killing," police Chief William Landsowne said Sunday, "this was an assassination."
Henwood, 36, had been a captain in the U.S. Marine Corps Reserves who had recently returned from a year's deployment in Afghanistan.
The armed suspect, Dejon Marquee White, 23, was tracked down by police and shot to death after the attack late Saturday afternoon. Investigators said they had no motives for the attack on the police officer.
Police said White left a two-page suicide note at his apartment, but it didn't say how he was going to kill himself or why.
The suspect had a minor criminal record that included resisting arrest and petty theft, Lansdowne said.
White had been a suspect in another shooting earlier Saturday at an In-N-Out Burger restaurant 14 miles away in El Cajon that left a man wounded and had eluded police after a high-speed chase.
Shortly after the restaurant shooting, Henwood was either stopped or moving slowly when a black Audi with temporary plates flashed its headlights and came alongside.
The suspect pulled up on the left side of Henwood's vehicle, pointed a gun out the passenger window and fired, police said.
The witnesses used Henwood's radio to call for help and gave him first aid until paramedics arrived and took Henwood to the hospital.
Shortly after the attack, officers tracked the Audi to an apartment complex and saw a man with a shotgun get in the car and start to drive away. Several squad cars blocked the road and converged on him to make the arrest.
Several officers fired at White when he grabbed the shotgun, the statement said. Officers pulled White from the car and called for paramedics. He was pronounced dead at the scene.
"We are saddened by this senseless and cowardly act that has taken away a true hero," said a written statement from Brian R. Marvel, president of the San Diego Police Officers Association, which established a trust fund for Henwood's family.
"Having recently returned from deployment in Afghanistan, Officer Henwood was continuing to serve the community just as he had served his country - with honor and respect," he said.
Henwood's killing comes as the department copes with the recent deaths of two off-duty officers. Det. Donna Williams, 52, was stabbed to death July 18 along with her daughter. Williams' 24-year-old son, Brian, who had a history of mental illness, was charged with two counts of murder.
David Hall, a 14-year department veteran, died Aug. 1 of an apparent self-inflicted gunshot wound. Hall, a motorcycle traffic officer, was awaiting trial on drunken driving and hit-and-run charges.
Henwood was the second San Diego officer to be killed while on duty in the last ten months. In July, three people were charged with murder in connection with an October 2010 shootout that killed Officer Christopher Wilson, a 17-year department veteran, and two others. The 50-year-old father of two was the first San Diego officer to be killed in the line of duty in more than six years.
"This tragedy is another grim reminder that our police officers put their lives on the line every day to protect our community, and we are grateful for their courage and sacrifice," San Diego mayor Jerry Sanders said in a statement Sunday.
In the earlier shooting at the restaurant in El Cajon, Martin Hanna was sitting with his girlfriend in his vehicle in the parking lot when he was approached by a man carrying a shotgun, police said. The man shot Hanna in the face with a single round before he fled in an Audi, they said.
Investigators had not established any relationship between White and Hanna, who was expected to survive.
Minutes later, an officer with no knowledge of that shooting spotted the Audi speeding and gave chase but abandoned the pursuit as it reached speeds of 100 mph. The attack on Henwood came shortly after that.
Associated Press writer Christopher Weber contributed to this report from Los Angeles.