ABC's Shushannah Walshe and Alex Perez report:
KILLEEN, Texas - When Spc. Ivan Lopez went on a shooting rampage Wednesday, killing three and wounding 16 at Fort Hood, there was at least one victim he knew: Private Deon Josephs.
Josephs' twin siblings, Deirdra and Darren Josephs, say Lopez and their brother were "friends."
"The shooter was from his same unit," Darren Josephs told ABC News in an emotional interview.
"The bullet is still in the back of his neck," Deirdra Josephs said, adding they have been told that until Deon's condition improves, "it's too dangerous to operate to get it out."
The family says Josephs was given a "50/50 chance" of survival when he arrived at the hospital. They say he was shot in the back, the bullet traveled up his spine, chipped an upper bone in the back, and hit a major artery.
The Josephs say he's lucky the bullet didn't hit his spine, but his spinal cord is "affected" and although he can move his fingers and toes right now "recovery will be a long, long process."
The siblings said their 31-year-old older brother had dreamed of joining the Army since he was a child, realizing that dream when he finished boot camp and became active duty in November. He was planning on being a career officer.
"I wasn't scared because he really wanted to do it, he really wanted to fight for our country, be a soldier," his sister said, adding her brother is a "fighter."
Their mother called Deirdra when she heard the news Wednesday, but Deirdra thought the nightmare would be impossible telling their mom, "No, he's fine, he's fine, he couldn't be part of this," but their phone calls and text messages went unanswered.
"That's all I hope for is that he's able to walk again and that he can stay in the Army, because that's his dream is to be in the Army, and to move up in rank," Darren Josephs said. "So it's a possibility he could regain all function and stay in the Army, but it's just too soon to know what's going to happen."
Before the rampage Lopez became enraged when an employee would not give him a leave of absence form, asking him to come back the next day. He returned moments later, but this time with a gun.
This weekend a new timeline was released by Fort Hood, detailing that lessons learned from the 2009 shooting may have sped up the response Wednesday. It showed that the first 9-11 call took place at 4:16pm at the first medical brigade building. Lopez then got in to his car, firing as he drove. After more than two blocks Lopez got out of his car where he was confronted by a female military police officer. She fired at him and he then turned the gun on himself.
At 4:20 p.m., four minutes after that first 911 call, first responders arrived at the scene, and by 4:43 p.m. the entire base was on lockdown. It took nearly four hours until 8:40 p.m. until that lockdown was finally lifted.
The memorial service for the Fort Hood shooting is scheduled for Wednesday. On Sunday the White House announced both President Obama and the first lady would attend.
Josephs' family has started a website to raise money for expenses at gofundme.com.
ABC's Tonya Kerr, Gina Sunseri, and Susan Aasen contributed to this report.