Zapata, Texas (CNN) -- The wife of an American man missing since a reported pirate attack on a U.S.-Mexico border lake said Thursday it's "hard being judged" by people who have questioned her story, but "I know what happened that day." 

Tiffany Hartley told authorities her husband David was shot and killed by pirates on Falcon Lake during a sightseeing trip last week. His body has yet to be found, leading to questions about the accuracy of her account. 

But Hartley told HLN's "Issues with Jane Velez-Mitchell" on Thursday that "I know what I know." 

"It's hard being judged and thought of that I might have done something to him," she said. But she added, "As long as I know the truth, God knows the truth. And other than that, it almost doesn't really matter to me, because I know what happened that day." 

Mexican authorities said earlier this week that they could not verify the shooting, and Hartley was asked point-blank on NBC's "Today" show Wednesday whether she had anything to do with her husband's disappearance. 

Pam Hartley, David Hartley's mother, said Tuesday that any suggestion that her daughter-in-law's account was inaccurate is "insane." 

Investigators have found some evidence that backs up Hartley's account, including blood on her life vest, Zapata County, Texas, Sheriff Sigifredo Gonzalez Jr. said Thursday. And the incident was similar to other attacks reported by boaters on Falcon Lake, about 70 miles west of the Hartley's home in McAllen. 

Gonzalez has said the gunmen are typically teenagers hired by a drug cartel in the neighboring Mexican state of Tamaulipas. Mexican authorities have said the lake is controlled on their side by "organized criminals," and the sheriff called on the Zeta cartel to turn over Hartley's remains if they have them. 
What was his wifes name?
Tiffany Hartley