The mother of the 18-year-old who shot a federal agent coming out of an Oakleaf Publix, then killed himself, said she can "only express my horror and grief" about her son Thomas Jacob Lewis and what he did.

"Although Jake no longer lived with me as a result of the structure and discipline that I attempted to place on him, I loved him dearly," Renee Lewis Homes wrote in a statement to the media. "… I would ask first for your prayers on behalf of the wounded officer and our law-enforcement community as they face danger every day. Second, I ask for your prayers for a grieving family that will try to remember Jake from better times. Finally if it is in your heart I ask for your prayers for the soul of my deceased son. Thank you for your patience and privacy during this difficult time."

The wounded agent serves with the U.S. Customs and Border Protection’s Air and Marine Operations assigned to Jacksonville’s National Air Security Operations Center, according to the agency. The Sheriff’s Office said he remains in critical condition. His name has not been released, and the Sheriff’s Office said it will not be providing any more information, saying the FBI is now handling the investigation.

The agent was in uniform as he carried groceries to his parked truck just after 3 p.m. when he was ambushed in the parking lot at 1075 Oakleaf Plantation Parkway, Chief Wayne McKinney said Tuesday. Lewis drove up behind him in a compact BMW convertible and opened fire, hitting him multiple times before driving off. Then Lewis shot himself and crashed into another car parked in the Publix lot.

McKinney said the two didn’t have any prior contact and the motive was unclear, but obviously the agent was targeted.

"It is something we live with each and every day knowing that going out in our community there are individuals who would target us just because of the badges we wear on our chest," the chief said.

McKinney said the agent never returned fire. Dozens of customers as well as employees at the Publix and a nearby insurance company heard the shots and cries of help from the injured agent. The sounds of gunfire and the speeding car sent them scurrying for cover, then some ran to help the injured agent, witnesses said.

Some speculated that Lewis may have thought he was being followed because he had a warrant out for his arrest on drug charges. His mother wrote that he was aware of it.

"He would still text me," Lewis Homes wrote. "When the Clay County Sheriff’s Office called me yesterday regarding his arrest warrant, I contacted Jake immediately and begged him to turn himself in."

His Facebook page says he went to Oakleaf High School.

Customs and Border Protection spokesman Keith Smith is working with Clay County officials on the assault and has reminded its law enforcement personnel "to be alert and aware of their surroundings and potential threats related to their service."

He also said that a number of people are donating blood for the agent at local OneBlood drives, including a Twitter post from Florida Highway Patrol Sgt. Dylan Bryan tweeting "Proud to donate for our brother @CustomsBorder @CBPFlorida today. Thank you for the community response for our fellow hero. #BackTheBlue."

Dan Scanlan: (904) 359-4549