The measures are in response to the killings of two Hopkins students during the past year, which sparked concerns about student safety around the university's Homewood campus in North Baltimore.
The increase would raise Hopkins' annual security budget by nearly 50 percent, bringing the total to about $6 million.
University officials said the figure could keep rising.
"Our eventual investment will be much more than that. But I pledge to you that we will spend whatever it takes to secure this community," Hopkins President William R. Brody said in an e-mail that was sent to students, parents and faculty yesterday.
Police continue to investigate the killing of Linda Trinh, a 21-year-old biomedical engineering major who was found dead in her off-campus apartment Jan. 23. There was no sign of forced entry, and investigators believe Trinh may have known her attacker.
In contrast, junior Christopher Elser is believed to have been fatally stabbed by a stranger who entered an off-campus fraternity house last spring.
Police believe Elser's death was a random, opportunistic killing.
After his death, Hopkins increased patrols and began installing video surveillance cameras and additional emergency phones on and off campus.
Brody's e-mail described 15 additional steps to improve security. Hopkins will immediately begin hiring off-duty Baltimore police officers to patrol the campus and nearby streets. They will wear their city uniforms and be armed. The officers will travel on foot and by car.
The university will also hire more private security guards to work in dorms and patrol the campus and the Charles Street corridor.
Brody said Hopkins also plans to install more video surveillance cameras and emergency phones, improve lighting at 22 locations, and appoint a group of outside experts to conduct a review of campus security.
Over the next three months, Brody said, the university will begin reconfiguring the lobbies of dorms so that anyone entering must pass through turnstiles and identify themselves to a guard.
Currently, students are guaranteed housing only through their sophomore years. The university recently broke ground on a new residence hall on Charles Street that will house 600 students. It is expected to open by fall of 2006.
"We are committed to meeting the need of our students for more university-owned housing, sufficient housing so that any undergraduate student who desires to live in a university building can do so," Brody wrote. About 4,000 undergraduates attend Hopkins.
Senior Jason Fodeman, who urged students to rally on campus last night, said the measures were "a step in the right direction" but should have been taken sooner.
About 75 students gathered in front of Brody's house, located on campus, at 9 p.m. Many echoed Fodeman's concerns that the administration had delayed implementing tighter security measures.
"The university has stonewalled students with promises they never fullfill," said Matt Emmett, 21, a Hopkins senior who attended the rally with friends.
One of them, senior Anna Rehwinkel, also 21, said students have been devastated by the killings of Trinh and Elser, who were both well-known and well-liked.
"People are fed up," Rehwinkel said. "This university has so much money, and it took until this for something to happen."
Brody, who greeted students in his driveway, told them "your security is extraordinarily important." He and Fodeman will meet to discuss security concerns at 9 a.m. today.
University officials said a memorial service for Trinh will be held at 10 a.m. tomorrow at the O'Connor Recreation Center on campus.
The $2 million for the changes Brody announced will come from the university's general fund as well as from the Krieger School of Arts and Sciences and the Whiting School of Engineering, officials said.
Sun staff writer Lynn Anderson contributed to this article.