As part of a national salute to slain law enforcement officers, President Obama paid tribute Wednesday to Plymouth Township Officer Bradley Fox, who was killed in September.

Fox was one of four officers singled out by the president during the National Peace Officers Memorial Service at the Capitol honoring those killed in the line of duty.

"The brave officers we gather to remember today devoted themselves so fully to others - to serve and to protect others - that in the process they were willing to give their lives. And so, today, let us not remember them just for how they died, but also for how they lived," Obama said.

"After serving two tours in Iraq as a Marine," he said, "Bradley Michael Fox retired with honor and followed his dream to becoming a police officer."

Fox and his police dog, Nick, were chasing a suspect, Andrew C. Thomas, when Thomas shot and killed the officer. Fox was the first Plymouth Township officer to die in the line of duty. He died the night before his 35th birthday and six months before the birth of his son, Bradley Michael Jr.

The ceremony Wednesday brought pride and tears to Fox's family and a contingent of colleagues who attended. Fox's parents; brother; wife, Lynsay; newborn Bradley; and daughter Kadence also were in Washington for the event.

"It was an emotional day anyhow, and to hear the president mention his name and where it happened, and the family - it made me cry a couple extra tears," said Police Chief Joseph Lawrence by phone just after the ceremony.

On Sept. 13, Fox was directing traffic around an accident on Ridge Pike when Thomas, 44, of Bala Cynwyd, ignored his directions and sped away in what authorities later learned was a stolen SUV. Thomas rammed another car as Fox chased him in his cruiser.

Thomas, an ex-convict, abandoned the SUV near the Schuylkill Trail and hid behind tall grass on a small hill. When Fox entered the area, Thomas fired four shots from his Beretta, hitting Fox in the head with one bullet and grazing the dog with another. Thomas then killed himself.

Since then, the Police Department and the community have rallied around Fox's wife and the couple's children.

The killing spurred tougher prison sentences, enacted this year, for straw purchasers of guns. A straw purchaser is someone who legally buys a gun for felons and others who are barred from possessing a firearm.

Investigators learned that Thomas had gotten the gun he used to kill Fox from a man who legally bought it for him.