A Lake County man jailed six months ago on weapon and parole violations has been indicted on federal murder charges in the Jan. 18 slaying of Kelseyville convenience store clerk, authorities said Friday.

Jonathan Antonio Mota, 31, also of Kelseyville, was indicted by a federal grand jury in San Francisco on Thursday night on four counts including robbery, use of a firearm in a murder and weapons violations, the U.S. Attorney's Office said.

He could face life imprisonment if convicted, the U.S. Attorney's Office said in a written statement.

The victim, Forrest Seagrave, 33, was gunned down at close range during a robbery at the Konocti Gas and Mart on Main Street, across from Kelseyville High School, authorities said.

Mota was a suspect within days, and on Jan. 26 was picked up for suspected possession of an assault weapon and violation of parole, District Attorney Don Anderson said.

"There is substantial evidence against him that he was the one who committed the robbery," Anderson said.

But authorities did not make public his suspected connection to Seagrave's case for undisclosed reasons.

"We had to keep it on the down low, for several reasons," Lake County Sheriff's Lt. Steve Brooks said Friday.

Mota was facing local charges for the assault weapon possession and parole violation when Lake County Sheriff Frank Rivero in February referred the case to the U.S. Attorney's Office, who took charge of it and took Mota into federal custody in April, Anderson and Brooks said.

It was unclear why the investigation fell within federal jurisdiction. Neither sheriff's officials nor the U.S. Attorney's office was immediately available for comment.

Anderson, who along with some other local policing officials has been locked in a feud with Rivero, said he regretted the move to take the case "away from the citizens of Lake County and put it in the hands of the citizens of San Francisco - solely because of his animosity toward me."

Brooks said sheriff's investigators worked jointly with representatives of the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, and the U.S. Attorney's Office to collect evidence in the case, including reviewing hundreds of hours of surveillance video.

Rivero has extended his thanks to federal officials and to his staff for what Brooks called "their dogged, non-stop efforts in solving the senseless murder."