GRAND PRAIRIE, Texas (CBSDFW.COM) – Grand Prairie Police have a man in custody after responding to a disturbance at a nail salon in the 5100 block of Magna Carta on Friday morning.

Police said investigators later determined the suspect was connected to a homicide.

When officers arrived at the nail salon, they were told a man came in with a pistol and began striking at least one female employee with the handgun.

Police said he also tried to start a fire at the nail salon.

nail salon in Grand Prairie (Chopper11)

A Good Samaritan with a concealed handgun license heard the disturbance and held the suspect at gunpoint until police arrived.

Police took the suspect, identified as Bill Son Nguyen, 47, into custody.

He is charged with murder, aggravated assault and arson.

Bill Son Nguyen – Grand Prairie homicide suspect

The woman who was struck went to the hospital and is expected to be okay.

While all of that was going on, the Grand Prairie Fire Department was putting out a fire in the 2900 block of Hastings Drive where there was a deceased person inside.

Investigators determined that home was connected to Nguyen.

As of 9:00 p.m. Friday, investigators were still out at the home on Hastings where a woman by the name of Chi Pham lived with her kids.

Friends say she is the woman who police found deceased.

Pham was raising her sister’s kids after her sister died last year, friends say.

The last time Lan Vo saw her friend Chi Pham, Pham had a new boyfriend.

“When we last talked, she had just started dating him. She told me that she was in a relationship,” said Vo.

Vo said her friend and single mom, Pham, was excited about the man she had just started dating, Billy Son Nguyen.

They met at the nail salon where they both worked.

Vo hasn’t seen her friend in months, until she heard her house caught fire this morning.

She rushed to the house where family sat on a lawn across from the devastation.

“I saw the house burning, all this smoke coming from the garage,” said neighbor Juan Carrasco.

“Her sister had died from cancer last year and left her three kids, so she is taking care of her own two kids as a single mom and then taking care of her sister’s kids on top of that,” said Vo.

Police said Bill Son Nguyen left Pham’s house after he set it on fire and then went to the nail salon where he pistol-whipped a woman and tried to set the salon on fire.

“I talked to her mom, I hear the kids crying in the back,” Vo said. “The first thing that come to my mind was how does a child deal when they come home to know that their mom is no longer there?”