DALLAS – Terrance King is Dallas's version of "Catch Me if You Can" -- only not very good at it.

King, 23, has repeatedly masqueraded as a doctor and as a firefighter, according to court and police records obtained by News 8. This week, authorities say he claimed to be doctor, sneaking into a patient's room at Children's Medical Center in Dallas.

He's back in the Dallas County jail after police say he stole an ambulance and wrecked it near the Medical District. His bail totals $12,000.

"Really, I think his motive is just he's always wanted to be some type of help - whether it's a paramedic, firefighter, police officer - since were younger," said Nikki King, his sister. "Even though he's committed these crimes, he's not the type to hurt anyone.

"He means well. He just goes about it the wrong way. He needs help."

She describes her younger brother as homeless, mentally ill, and sometimes delusional. She says she asked her brother why he does it, but he can't really give a good answer.

Stormy Howland, a former Dallas police sergeant, said she and her husband met Terrance King in Northeast Dallas when he was seven years old. She calls him "Terry."

"He's been obsessed with police and the fire department, especially the fire department, since he was a little boy," Howland said. "That was his dream."

As a teenager, he ended up in the foster care system after his mother died of kidney failure in 2007. When he turned 18, Howland says the state gave him $500 and "said goodbye, no guidance, nothing," she said.

She and her then-husband took him in for a time, but eventually, when he started getting in legal trouble, she said they told him he couldn't live there.

"If he takes his medications, he's great," Howland said. "He's like a normal person. Terry normally does these things when he's seeking shelter and food. He's just been in survival mode, but he's not in the right survival mode, because he's not thinking clearly."

Terrance King first made headlines in 2013.

In April 2013, King was arrested after posing as a Dallas firefighter at Plano firehouse. Authorities say he showed up at the fire station, dressed in a Dallas firefighter's uniform, asking for a ride-along. He even ate breakfast with the firefighters. When he couldn't produce an ID, they realized he was an impostor.

"The first time, I was extremely shocked," Nikki King said. "I thought this can't be my brother."

A few months later, according to Irving police records, Terrance King posed as a "Denton fire department member." He was wearing a stolen shirt and jacket emblazoned with the Denton fire department name and logo. King told hospital staff members that his name was "Hunter Hudson" with the Denton Fire Department. He was carrying a handheld radio taken from Denton Presbyterian Hospital, the affidavit says.

He was arrested on a charge accusing him of impersonating a public servant.

In January 2014, using a stolen key card, he masqueraded as a doctor at Forest Park Medical Center on the North Central Expressway, according to police records. He went to the cafeteria and took two muffins. He told a hospital vice president that he was "Dr. Starr" and was wearing a lab coat with that name embroidered on it. The key card and coat belonged to the real doctor, who worked at the hospital.

The vice president thought something wasn't right about "Dr. Starr," so he notified hospital security, who determined it was an impostor.

King returned almost a week later, again using the stolen key card to enter through a restricted access door "with intent to take more food." King told police that he had been entering the hospital for about a week. During that time, food and drink items had been going missing, the report said.

"Security guards have noticed [Terrance King] who has been identifying himself as a doctor, and was not investigated until he encountered" the vice president, the report said.

He told police that he had been taking shelter inside hospitals and the Salvation Army. Police found him with two laptops that had been taken during a burglary at Presbyterian Hospital in Plano, the report said.

He was sentenced to 45 days in jail on a burglary of a building charge.

In July 2014, surveillance video captured King walking into the University Park fire station and taking a handheld radio.

"Later in the day, he acted like he was with the Dallas Fire Department and called in a suspicious person at a park," said Officer Lita Snellgrove, a police spokeswoman. "He did it a couple of different times."

She says University Park police eventually identified him as a suspect based on what had happened in Plano. He was charged with felony theft a couple months later. The radio was also recovered around that time at an apartment on SMU Boulevard, where he had lived.

"He has done this numerous times," Snellgrove said. "He'll get locked up and says he's reformed, and the next thing you know, he's out doing it again."

King was most recently released from jail on May 20 after serving a sentence on the University Park police case.

About 9:10 a.m. Tuesday, hospital officials alerted security to a possible impostor, according to a police bulletin obtained by News 8. According to the bulletin, a security officer was initially told that the "person in question, a Doctor Munoz, was legitimate." About 20 minutes later, a nurse informed security that "Dr. Munoz" could not "produce adequate ID."

Another nurse told police that she saw the man enter a "patient room, look around and come out. When he came out, he stated, 'He doesn't have anything wrong,'" the bulletin said. "She asked him what he meant and he mumbled."

The nurse saw that he had a visitor badge and asked for his hospital badge, which he said he did not have with him. The man was wearing a white lab coat with "Texas Oncology" on it. He told her was connected to Medical City.

The records show he was then reissued another visitor's badge because he had previously been issued one from the night before.

"If a visitor comes in and can say, 'here's who I'm here to see' and has their picture made and information recorded, we're set up to allow visitor's access," said Randy Sachs, a hospital spokesman.

The man, later identified as King, also named a real doctor at the hospital who he claimed he was supposed to shadow.

"This doctor said no one was scheduled to shadow her," the bulletin said.

Shortly before 10 p.m. Tuesday, an ambulance was taken near Medical City. The engine was running. The keys were in the ignition. Police officials began tracking the ambulance through its tracking system.

Dallas police spotted the vehicle, but did not chase it because department policy forbids it. At one point, the driver turned on the lights and sirens of the ambulance.

The vehicle was tracked to Parkland Hospital where the driver drove into the emergency entrance.

A Dallas police officer spotted the ambulance. The driver fled out the emergency entrance, driving the wrong way. A Parkland Hospital police officer then began to chase the ambulance, according to the arrest warrant affidavit.

The hospital police officer wrote that he lost sight of the ambulance and then saw that it had wrecked out near the intersection of Maple and Oak Lawn Avenues. The ambulance had run a red light and plowed into a BMW driven by a doctor.

The force of the collision sent the car airborne and spinning through the intersection, said the doctor's wife, who also in the car.

The driver, identified as King, fled on foot.

He ran up to a motorist, asking, "Can I get a ride to a bus station? I just stole that ambulance." The motorist told him, "No."

King was soon taken into custody.

The doctor's wife, who asked not to be identified, questioned why hospital police would chase in such a busy metro area. The force of the collision also threw their black lab/pit bull mix named Annie from the car.

"We're just covered in bruises and swelling and soreness," she said. "I don't appreciate being collateral damage to a cop driving that fast after a stolen vehicle."

A Parkland Hospital spokeswoman declined to comment on the chase and the hospital's chase policy.

Tawnya Silloway, an AMR spokeswoman, said that is a fairly regular occurrence because "there's so many folks around." She said the incident would be investigated to determine what could be done differently.

Nikki King, Terrance King's older sister, offered her apologies to the doctor and his wife on her brother's behalf.

"I'm not surprised at the action," Nikki King said. "I'm surprised at the time that it occurred -- that he just got out of jail. [He was] writing me this whole time saying, 'I'm going to get my life together. I'm going to do this and do this and that.' And a week later, [he's] back into it."

Both Nikki King and Howland said they hope that Terrance King gets the help he needs this time.

"Our justice system needs to figure out the difference between a true criminal and someone that is committing crimes because they have a true mental illness," Howland said. "He needs to be committed to a long-term program rather than being in jail. Being in jail is not going to help him."