Even though investigators haven't found any physical evidence linking the Saturday deaths of McLelland and his wife, Cynthia, with the Jan. 31 slaying of Assistant District Attorney Mark Hasse, who was shot and killed in a parking lot, Wood said Monday he believed the two incidents were related, the Fort Worth Star-Telegram reported.
"There has to be a connection, in my way of thinking," Wood said.
Security was enhanced at the Kaufman County Courthouse and the district attorney's office was closed Monday as authorities searched for suspects.
Sheriff David Byrnes said he won't link the deaths of the McLellands to Hasse's slaying, the Star-Telegram reported Sunday.
Asked if McLelland, 63, was concerned about being a target, Byrnes said the prosecutor didn't discuss it.
"Not to me," Byrnes said.
At a news conference Sunday, Byrnes wouldn't speculate on a motive for the McLelland killings.
"We are not going into any details because it's an ongoing investigation," he said.
Byrnes said he and other authorities have considered that other county officials could be targets.
"Certainly, we're considering that, obviously," he said.
Deputies were called to the district attorney's home Saturday evening by a law enforcement friend who had stopped by to check on them, WFAA-TV, Dallas, said. Investigators told reporters the front door was open and the McLellands were found shot with what is believed to be an assault rifle.