He said he noticed a vehicle he believed belonged to media photographers, then saw members of his security team drive past it.
According to his statement, the situation escalated when a man approached him.
He said a man “turned and faced me – he was wearing a balaclava face covering,” Metro UK reported.
Mountbatten-Windsor described the man as “out of place”.
“I then saw a loose dog running towards him,” the statement continued.
“Then he realised who I was and began to sprint after my vehicle.”
The proceedings then turned to whether Jenkinson could enter the court after arriving with his dog, Indie.
Defence lawyer Claire Howell told Judge Tan Ikram that the dog served as her client’s support animal, Metro UK reported. She said Jenkinson has ADHD, is homeless, and had nowhere suitable to leave the animal while attending court.
However, she acknowledged she was unable to provide documentation verifying his medical condition or need for a support animal, according to the outlet.
“We accommodate people who have ADHD and have support animals,” Judge Ikram said, but he wanted more proof than “he is homeless and happens to have a dog”, Metro UK reported.
The hearing proceeded without Jenkinson after he was refused entry.
Jenkinson has pleaded not guilty to the public order charge involving Mountbatten-Windsor. He has also denied a separate allegation that he used threatening, abusive or insulting words or behaviour with the intention of causing fear or inciting unlawful violence against another man named Stephen Terry.
The 39-year-old, from Stowmarket, Suffolk, is also contesting a proposed Stalking Protection Order against him.
Jenkinson remains on conditional bail while the case proceeds. Under its terms, he is prohibited from going near Sandringham, Buckingham Palace, Balmoral, Windsor or Highgrove, the BBC reported.
He is also barred from contacting Mountbatten-Windsor, directly or indirectly, and must not approach him or enter Norfolk.