Sapper Walker was killed and six others injured when the Afghan soldier opened fire on international and ANA troops.
He leaves behind a young daughter, Lilly-Faith, who he had only known for 18 months before he was deployed for his first tour of Afghanistan in September.
"Richard held two things close to his heart - his daughter and his colleagues
in the Army.
A proud, patriotic man, he died doing a job he loved, supporting his friends."
- Family of Sapper Walker
"Sapper Walker was the epitome of a true Sapper, one who would roll up his sleeves and get on with the task in hand no matter what, but importantly he would do it with great humour."
- Lieutenant Colonel Chas Story, Commanding Officer, 28 Engineer Regiment
At 11am, Sedgefield village green fell silent as veterans paid their respects once again.
It has become a local focal point for many as members of Sedgefield Village Veterans gather to mark each loss.
It was confirmed yesterday that another British soldier died in hospital from wounds suffered in combat in Afghanistan. He was from 1st Battalion The Duke of Lancaster's Regiment and was flown back to Britain for treatment.
The number of members of UK forces to have died since operations in Afghanistan began in October 2001 now stands at 440.
More top news
A Seaham man who tricked children into sending nude selfies then blackmailed them into sexually abusing others has had his sentence extended
A priest who was jailed for 17 years after sexually abusing a teenage boy has won the first stage of his fight to clear his name.
Football presenter Jeff Stelling and the family of Bradley Lowery have been recognised for their fundraising at the JustGiving awards.