DENVER (CBS4) – A legal battle is ramping up after an incident at the Denver Zoo where a man died one year ago after being tased by police.

Now the family of Alonzo Ashley is suing the city and the people it blames for his death.

Everyone from the city and county of Denver to individual officers and even Denver Zoological Foundation employees are named in the 17 page lawsuit.

The suit is filed on behalf of the estate of Alonzo Ashley and claims that Ashley’s death was avoidable. It explains details about what happened that day that led up to Ashley being tased and beaten by Denver police officers. It also notes that Ashley was unarmed and claims that he never put officers’ lives in danger.

The suit describes the emotional and financial distress Ashley’s family went through because of his death. CBS4 talked with Ashley’s family just after the incident happened last July.

“If he’s already on the ground there’s no reason to tase anybody, and he’s about my size. It doesn’t take seven or eight officers and zoo security to pin anyone down,” the family member said.

“The officers did what they needed to do and used minimal force necessary,” said former Police Chief Gerry Whitman at the time.

The coroner’s report states that Ashley died from cardiorespiratory arrest. Tests were negative for all drugs except marijuana.

Ashley’s family held a vigil at the Denver Zoo Wednesday evening.

“It’s been horrific, it’s been a hurtful year for me, no closure,” Ashley’s brother Lendell Ashley said.

Lendell Ashley says he still misses his only brother and one year after his death, the pain hasn’t gone away.

“Hurtful, there’s been ups and downs, it’s been hurtful and very painful,” he said. “Hopefully something will come out during the trial and the (district attorney) will say we need to file charges, we need to file criminal charges, because no amount of money in this world that will replace my brother.”

The city attorney released a statement saying the city stands firm that the zoo and its officials, the city of Denver and police officers acted entirely appropriately in responding to the situation.

“We extend our continued sympathies to Alonzo Ashley’s family and loved ones on the anniversary of his death,” the statement said.

The district attorney did not file criminal charges in the case against the zoo security guard, the witnesses that got involved, or the eight Denver police officers.