LASALLE, Colo. -- A year after her husband was gunned down by drug gang members on a Mexico-Texas border lake, Tiffany Hartley told 7NEWS she's still pressing the federal government to find David Hartley's body and bring his killers to justice.

Last week, Tiffany Hartley sued the U.S State Department, the Justice Department and the FBI to try to get answers about her husband's death.

"I'm here a year later, fighting for the same thing I was a year ago and that's ultimately getting David back and bringing him home and finding the people who did this and finding justice," Hartley told 7NEWS reporter Jaclyn Allen on her family's LaSalle farm on Sunday night.

Tiffany still wears her and her husband's wedding rings. The couple had removed the bands on Sept. 20, 2010, before they took an ill-fated Jet Ski outing on Falcon Lake along the U.S.-Mexico border.

Armed men in speed boats began chasing the couple, she said. They tried to flee, but David Hartley was shot.

Tiffany Hartley said she tried to pull her husband's limp body onto her Jet Ski, but as the gunmen closed in, she was forced to leave him and escape.

The widow testified at a congressional field hearing in Brownsville, Texas, last week in support of boosting the number of border patrol officers.

"I had to make that decision to leave him behind and hopefully make it across," she told the panel. "It's only by the grace of God that I’m here today."

The couple was originally from Loveland and had been planning to move back to Colorado from Texas, where David Hartley worked in the oil industry