The San Francisco Police Department did not return phone calls Sunday.
"The San Francisco Police Department has provided us an initial investigation," Gascon said in a written statement Friday night. "However, not all witnesses have been interviewed, nor have any independent witnesses of the incident been interviewed. We have requested this and other evidence be collected before we can make an assessment on whether charges should be filed."
Denver was stabbed to death Wednesday after attending the game with his brother, father and two others to celebrate his father's 49th birthday. Denver lived in Fort Bragg, a Northern California city about 170 miles north of San Francisco.
Police have said Denver's group, many wearing Dodgers garb, left AT&T Park after the eighth inning to head to a nearby bar. At some point, they got into a shouting match over the Dodgers with Montgomery and a few friends who were bar-hopping in the trendy South of Market area. At least one was wearing a Giants cap.
"The back and forth, 'Go Dodgers!' 'Go Giants!'" Police Chief Greg Suhr said. "And it deteriorated from there."
Suhr said Montgomery made "incriminating statements" that led to his booking the night after the stabbing.
Montgomery's father told the Lodi News-Sentinel that his son was jumped during the fight, and he stabbed Denver in self-defense after Denver and others yelled "Giants suck." The father told the News-Sentinel that his son said Denver hit him over the head with a chair during the fight a few blocks from the stadium.
A second suspect was questioned and released by police Friday. Two others were being sought.
The stabbing was the latest incident over the years stemming from one of the most passionate rivalries in sports. Two years ago, Giants fan Bryan Stow suffered permanent brain damage when he was attacked in Los Angeles.