It happened Monday at the Jupiter House after a man was reportedly being belligerent and refusing to leave.
Employees say they called police, but the suspect, 25-year-old Michael Cook struggled with officers, who say Cook slammed his head into the front door, shattering it.
The arrest affidavit says Cook was tased three times outside, then walked inside with two prongs still attached to him.
A customer's cell phone video shows officers perform a "drive stun" on Cook, allowing officers to tackle him and take him into custody.
Around 1 p.m. Monday, Justin Kowalick says he struck up a conversation with his friend, Cook.
"Who you're dating, how your job is going, stuff like that," said Kowalick. "That day, he did nothing but spout vulgar, violent word salads."
Kowalick says Cook seemed out of it.
"He looked malnourished," said Kowalick. "He looked like he hasn't slept in a week."
After stirring up trouble, showing odd, antagonizing and aggressive behavior, the coffee house says it called police to issue a no trespass.
Officers did, but Cook came back. According to the arrest affidavit, officers called for backup as Cook fought with them.
"He's screaming, ‘If I go to jail, I'm going to kill you all,'" said Kowalick.
Officers then tased Cook as he intentionally smashed his head into the front door, cutting himself.
Police say protocol is to activate the taser for five seconds, but this was going on eight seconds.
When Police tased him a second time, documents say Cook took a prong out, so he was tased a third time.
With two prongs still in him, Cook walked inside the shop and past witness Brad Santulli.
"It was coming towards me and I figured I might as well capture it," said Santulli.
His cell phone video shows Cook still on his feet after getting tased three times.
Finally, police attempt a "drive stun" –- a fourth shock.
"He continued walking towards the counter, was continuing to be belligerent and they finally brought him to the ground after a third officer arrived," said Santulli.
With Cook appearing unstable in a coffee house full of customers, witnesses credit Denton police with saving lives.
"I would commend the officers for handling it appropriately for doing the job they're supposed to," said Santulli.
Cook has two prior convictions for criminal trespass, but from this incident, he faces four charges: criminal trespass, resisting arrest, criminal mischief and giving a fake name to officers.