HOUSTON, Texas (KTRK) -- A deadly stabbing that happened onboard a METRORail in downtown Houston on Monday night will be referred to a grand jury, the Houston Police Department said in an update on Tuesday morning.
METRO police Chief Vera Bumpers says the stabbing happened between 7 p.m. and 7:30 p.m. at 1150 Rusk St. on METRO's Purple Line. Houston police took over the investigation after the man died.
RELATED: Police respond to deadly stabbing along METRORail line in downtown
According to HPD, METRO police officers responded to a stabbing call on a METRORail train, where they found a man sitting on a bench outside the railcar.
Another man was found with stab wounds inside the railcar. Witnesses say they saw paramedics performing CPR, but the man died of multiple stab wounds.
Chief Bumpers told ABC13 she viewed METRO surveillance video that captured the stabbing.
"It appears that deceased was the aggressor based on the video footage," Bumpers said. "I'm sure that's why the charges are not filed and they referred to the grand jury."
Bumpers said both men might have been homeless, because they carried all their belongings with them to the light rail stop. At some point, the argument escalated.
"The deceased had a screw driver and the other person had a knife," she said. "There were two weapons involved."
After authorities spoke to the Harris County District Attorney's Office, it was determined the case would go to a grand jury for review.
Police say there's no continuous threat to the public after Monday's stabbing, which also marked the second-such killing on METRORail's Purple Line in a month. A 28-year-old woman was attacked at the Palm Center Station on Oct. 29.
METRO police say it is increasing staffing and presence on the Purple Line, but that the trains are as safe as can be.
For news updates, follow Miya Shay on Facebook, Twitter and Instagram.