Rudy Acosta was just weeks away from coming home to Santa Clarita from his deployment overseas when he and a group of unarmed soldiers were ambushed. Two soldiers died and three others were injured.
That's according to a wrongful death lawsuit filed by his parents in July.
Pfc. Acosta was 19 when he was killed in March 2011 inside a secure area of the Forward Operating Base Frontenac in Afghanistan.
Read the original story on NBCLosAngeles.com.
The combat medic was shot to death on base by an Afghan national hired to protect the military -- a man who had previously allegedly threatened to kill U.S. troops, according to the lawsuit filed by Dante and Carolyn Acosta in federal court.
"We lost our oldest son. We lost a bright, funny, charismatic 19-year-old young man with a bright future. He wanted to be a surgeon," Dante Acosta, Rudy's father, said.
The Acostas are suing the private security company, Tundra Group, based in Canada, saying that the firm rehired Shir Ahmed after previously firing him for making the threats.
According to the lawsuit, Ahmed was hired in May 2010 and fired in July of the same year after making statements about killing U.S. personnel. Tundra recommended he not be rehired but the recommendation never entered his file and Ahmed was rehired in March 2011, the lawsuit claims.
The Acostas' Los Angeles attorney, Stuart Fraenkel, said Ahmed was given body armor and a loaded AK-47 weapon.
The lawsuit states that Tundra entered into an agreement with the American government in November 2009 to "among other things, screen, evaluate and monitor private security guards at nine military installations, including FOB Frontenac. The agreement required Tundra perform ordinary and necessary safety precautions to protect the men and women, living, working and servicing at FOB Frontenac."
"They have customs, practices, procedures, protocols in place to prevent this kind of a problem from happening and they didn't follow them," said Fraenkel, who is also representing three others injured in the attack.
The plaintiffs are seeking unspecified punitive damages.
The incident is among those considered by the government as "green on blue" or "insider" attacks, which have been a major focus in Afghanistan this summer. The attacks occur when members of the Afghan National Security Forces turn their guns on coalition members.
According to a U.S. Department of Defense spokesman, there have been three such incidents involving private security contractors.
There have also been 32 other green-on-blue attacks so far this year -- 11 more than all of 2011 -- the Defense Department spokesman said in an email. Since 2007, there have been a total of 73 "insider" attacks resulting in dozens of deaths and over 100 U.S. personnel injured.
Just in the month of August 2012, there have been 10 insider attacks that killed 10 Americans, the Associated Press reported Thursday.
That is in part why the Acostas vow to continue their fight.
"They need to be held accountable, or this could happen again," Carolyn Acosta said.
The Acostas say Tundra has not contacted them since their son's death. Tundra did not respond to NBC4's request for comment.
The House Armed Services Committee, led by Chairman Howard "Buck" McKeon, R-Calif., held two hearings on "insider" attacks, including one specifically about Rudy Acosta in February.
Rep. Duncan Hunter, R-Calif., sent a letter to McKeon asking for another hearing on insider attacks, or "at the very least request a briefing by the proper Department of Defense officials." No hearing has been scheduled at this time.
On Thursday, a top U.S. commander in Afghanistan said that the recent rise in insider killings can be attributed in part to stress on Afghan forces from fasting during the just-ended Muslim holy month of Ramadan, the Associated Press reported.
But that doesn't explain what happened in Acosta's killing.
Since his death, procedures for U.S. troops in Afghanistan have changed. Troops have now been ordered to carry their weapons loaded at all times to counter any such attacks.
Fraenkel said he believes Tundra continues to perform services for the U.S. government.
The lawsuit states that Rudy Acosta had plans to get married and attend medical school when his service was complete.
This story originally appeared on NBCLosAngeles.
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