Chris Van Horne, nbcdfw.com
Friends and family mourn the loss of a father of two shot and killed in Fort Worth.
Fort Worth police officers took several people into custody Tuesday after an early-morning fatal shooting and standoff on the city's south side.
Police officers looking for the people involved in a fatal shooting in the 1900 block of Grainger Street cordoned off an area near Main Street and East Allen Avenue in the hospital district after 7 a.m. after witnesses directed officers to a nearby home.
Zero Tolerance tactical officers surrounded the home and waited for a judge's signature on a warrant to proceed further.
John Peter Smith Hospital earlier said the officers were SWAT officers. A SWAT team was not at the scene but was put on standby, Sgt. Pedro Criado said.
Several buildings were evacuated, including one used by JPS Hospital for information technology services, for use as a staging area for planning and negotiations.
The JPS building, which is across the street from the main hospital, does not house any patients. Patient care at the hospital was not affected.
Initial reports of a gunman inside the JPS facility were false.
Just after 10 a.m., the people inside the home surrendered. Officers handcuffed five people from a home near the 1700 block of Galveston and Jefferson avenues.
Investigators said the shooting might be the result of a fight between several people, including the victim.
Police have not released the victim's identity, but family members identified him as 24-year-old Julius Isaac.
Isaac's girlfriend, Asia Jefferson, said they had two boys who were 4 and 6 months old. She said Isaac was a great father.
"JuJu was the best daddy to his boys. You cannot separate him from his kids," she said. "JuJu was a good person. He was my best friend. He was a great father. And if you met JuJu, everybody said the same thing about JuJu -- he [is] nice, he'll make you laugh and don't do nothing to nobody. He was just an all-around good person."
Jefferson said she wasn't sure why Isaac was at the location of the shooting.
A neighbor of the apartment where Isaac was killed, Tawatana Ware, said she heard two gunshots and then people running down the stairs.
She said she was on the phone with 911 dispatchers when she saw Isaac. She said he was already dead.
Ware and Isaac's cousin, Louis Shannon, said the shooters were looking for someone else and shot Isaac by mistake.
"I think the shooter had a problem with another friend of ours, and I think the bullet was meant for him," Ware said.
"They mistook him for somebody else and shot him and took off like cowards," Shannon said.
Police said the investigation is in its early stages and that investigators would look at all possibilities in Isaac's slaying.
Police confirmed that they have been called out to the Grainger Street address several times. Police reports indicate there have been four such calls since late September.
In three of those reports, the same woman said she was threatened by someone who was going to "shoot up her apartment."
The first incident happened at about 10 p.m. on Oct. 23. The victim was receiving harassing telephone calls from a blocked number, according to the report.
"The VIC stated the SUS told her he was 'going to shoot up her apartment.' The VIC does not know why the SUS is harassing her. The VIC feels threatened by these phone calls. The VIC has asked the SUS to stop harassing her," the report states.
Three days later, a man knocked on the victim's door. She said the man threatened her again and asked about the whereabouts of someone.
"VIC said that SUS1 came by her apartment and threatened he was going to shoot up her apartment again," a police report stated. "VIC said that SUS1 kept asking her 'Where is he?' VIC asked SUS1 where's who. VIC said SUS1 said 'you know who where is he?' VIC said that SUS1 displayed a silver handgun, but did not pull it out and told her again he was going to shoot up her apartment. VIC was in imminent fear of her life and believed that SUS1 would do what he said he was going to do."
The report on Oct. 26 said that while the officer was typing up his initial report down the street, the victim called to say the man had returned and continued to threaten her. The officer gave the victim additional contact information and told her not to open up the door again.
A day later, a man threatened to kill the same woman, according to another police report.
Police have not said what charges, if any, the people in custody may face.
A separate and unrelated incident of an armed person on the 4700 block of Bryant Irvin Road was cleared by officers with no incident.
NBC 5's Deborah Ferguson and Ben Russell contributed to this report.