WATCH: Newly Released Photos Show Injuries of Unarmed Man Killed by El Paso Cop

EL PASO, Texas — An El Paso police officer who shot and killed a man outside the downtown jail heads to civil trial in federal court Friday.

KFOX14 Investigates obtained new documents and photos which now show a new side to the case.

Officer Jose Flores was fired by the El Paso Police Department in October of 2014.

This was after he killed Daniel Saenz, a local bodybuilder, outside the downtown jail in March of 2013.

Saenz was unarmed and handcuffed at the time.

Flores won an appeal and was re-instated as a police officer in 2016.

A grand jury chose not to indict Flores on criminal charges. But Saenz’s family has now brought a civil suit against Flores.

The suit alleges Flores violated Saenz’s civil rights and that Flores admitted that his shooting of Saenz wasn’t justified.

Newly obtained documents from the Fifth Circuit Court of Appeals, shows the injuries Saenz sustained while in custody and an alleged motive for what happened.

In March 2013, Saenz appeared to be having an emotional episode at an Albertsons and was reportedly crying and asking for hugs.

This led to him being taken to the hospital where he punched a female officer in the face.

Court documents now show photos of her injuries.

Court documents allege that when Flores started his shift he was angry that his friend and coworker had been hurt and “decided to take revenge.”

Photos show an uninjured Saenz before he was taken downtown by Flores.

The Saenz family attorneys claim that on the way to the jail, Saenz’s head banged against the transport van multiple times.

The attorneys also allege that surveillance video shows Flores pushing Saenz through the jail door, causing a severe head injury that was gushing blood.

The large cut is documented in photos obtained by KFOX14 Investigates.

Documents say Flores was advised the head injury was life-threatening and needed urgent care, but that Flores refused to get Saenz aid.

Attorneys go on to state, Flores dragged the semi-conscious Saenz up and down the jail facility for more than an hour. With an extensive trail of blood behind them.

Then Saenz was allegedly taken to an area where there were no cameras — and prisoners allegedly heard Saenz being beaten.

Photos obtained by KFOX14 Investigates are too graphic to show you but they show Saenz’s face and head are very bloody and injured. Those injuries are documented by the medical examiner.

His arms were also injured.

The attorneys go on to say, Saenz was “mercilessly” beaten about his body and head by Flores.

Documents state that “no reasonable police officer would inflict the life-threatening injuries on a detainee the way Flores did.”

“An angry and pissed off Flores took Saenz outside the jail,” the documents state Flores went back in the jail, pulled his a gun out of a locker, went back outside, woke up Saenz, struggled with him and shot him.