Officials identified the police officer killed in the line of duty as Garrett Swasey and on Sunday officials preliminarily identified the two other victims as Jennifer Markovsky and Ke'Arre Stewart.
Markovsky and Stewart were both accompanying separate friends to the clinic, the Associated Press reported.
Note: This post will be updated as more information becomes available.
Jennifer Markovsky, 36, Colorado Springs
She leaves behind a husband, Paul, as well as a son and a daughter.
The family had been in Colorado Springs since at least 2008, a neighbor told BuzzFeed News, describing her as a "sweet and good neighbor."
Markovsky graduated from Waianae High School on Oahu in 1997, according to Hawaii News Now.
Her father, John Ah-King, announced her death on Sunday on his Facebook page.
“To my daughter Jennifer, I'm going to miss so much,” he wrote. “…Life was [too] short my beloved daughter, I was waiting to see you soon, I'm going to miss you, my [memories] of you will live on in my heart and mind.”
Many other relatives also posted tributes to Markovsky on her Facebook page.
“My dear sister in law, a selfless friend and a dedicated mother and wife,” Julia Miller wrote. “You will truly be missed, but not forgotten.”
Miller told the Denver Post that her sister-in-law had lived in Colorado for about two decades after her husband was stationed there for the military.
Miller said that the couple had met in Hawaii when Paul Markovsky was stationed there.
A relative of Markovsky’s told Hawaii News Now that she had been at the Colorado Springs clinic to support a friend.
Markovsky’s Facebook page paints an idyllic picture of a happy family that loved to explore the nature around them in Colorado.
"I love taking pictures of nature," she wrote.
She often posted about her two children and their accomplishments, and was an active supporter of March of Dimes, a charity supporting babies born prematurely.
An online fundraiser has been set up on YouCaring to support the family.
Ke'Arre Stewart, 29, Colorado Springs
Ke'Arre Stewart, an Army veteran who did a tour in Iraq, was among the three people killed in the Planned Parenthood Colorado Springs shooting, a friend told BuzzFeed News.
Amburh Butler said she grew up with Stewart in Waco, Texas, and the pair dated through middle school and high school.
The pair broke up shortly after Stewart joined the Army in 2004, Butler said, but the two kept in touch. Butler enlisted herself in 2005 and is currently a human resources sergeant for the Army.
“He would talk to anybody, very nice, down to dart, very Southern,” she said. “If you needed something he would move hills to get it for you.”
Butler last spoke with Stewart by phone on Thanksgiving. She said Stewart told her he wanted to open a trucking company, an industry that interested him because his mother used to drive trucks before she retired.
Stewart was living in Colorado Springs and was discharged from the Army after serving as an infantryman, Butler said. A U.S. Army spokesperson on Sunday told BuzzFeed News they were unable to immediately verify the details of his service or rank.
On Facebook, Stewart was mourned by his younger brother, who said he served in Iraq and left behind two daughters. "I just ask for help, love, and [the] support of my family," the grieving sibling wrote.
After being shot, Stewart ran back into the building to warn others to take cover, his brother, Leyonte Chandler told NBC News.
"I believe that's his military instinct, you know: Leave no soldier behind, leave no civilian behind," Chandler told NBC News. "So he ran back inside, trying to help out others. I don't know where he was at, as far as how many more breaths he had, but he knew. And before his time ran out I guess that was his main priority ... to help and save other lives."
Stewart ultimately left the Army, Butler said, because he wanted to do something different with his life and was haunted by the loss of some of his friends who served with him.
“It’s sad that a person goes and puts their life on the line for their country and yet they die because of a maniac here in the States,” Butler said.
Butler started a GoFundMe page to help the family pay for funeral expenses in Texas.
Garrett Swasey, 44, Colorado Springs
Officer Swasey was a six-year veteran of the University of Colorado Colorado Springs' police department.
"Helping others brought him deep satisfaction and being a police officer was a part of him," Swasey's wife, Rachel, said in a statement Sunday. "In the end, his last act was for the safety and wellbeing of others and was a tribute to his life."
In a statement, university chancellor Pam Shockley Zalabak said: "It is with great sadness that I share that the tragic events today at the offices of Planned Parenthood in Colorado Springs have touched the campus of the University of Colorado Colorado Springs."
University of Colorado President Bruce Benson also released a statement mourning Swasey.
"The CU community mourns the tragic loss of Officer Garrett Swasey of UCCS. Our thoughts, prayers are with Rachel, their children and family," Benson said.
Swasey is survived by his wife of 17 years, Rachel; a son, Elijah; and a daughter, Faith.
"His greatest joys were his family, his church, and his profession," Rachel said. "We will cherish his memory, especially those times he spent tossing the football to his son and snuggling with his daughter on the couch."
Born in Melrose, Massachusetts, Swasey was a champion ice-skater during the 1990s before he became a police officer. He was also an elder in northeast Colorado Springs church Hope Chapel.
According to the church website, he helped oversee the church's care groups in addition to "sharing his teaching gift as part of the teaching team and sharing his guitar skills on the worship team."
A co-pastor at the church, Scott Dontanville, told the New York Times that Swasey would "disagree with the abortion industry...I don’t think that was on his mind. He was there to save lives. That’s the kind of guy he is.”
On Facebook, Kimberly Swasey Noveltsky wrote of "the devastating news that [her] brother Garrett Swasey had been killed in the line of duty."
“He was kind,” his mother told the Washington Post in a phone interview. “He wasn’t arrogant or selfish, and I wish people could hear more about that, about how caring the police really are.”
Early Saturday, fellow police officers and other first responders held a procession and escorted the body of Officer Swasey from the crime scene.
President Obama also praised the slain officer's valor in a statement on Saturday. “May God bless Officer Garrett Swasey and the Americans he tried to save — and may he grant the rest of us the courage to do the same thing," Obama said.
On Saturday night, more than 200 university students, Colorado Springs residents, officers, and church members gathered for a candlelight vigil to remember Swasey.
Campus police chief Brian McPike described Swasey as an athletic, enthusiastic police officer who always walked into a room with a smile on his face. McPike had known Swasey before becoming chief and recommended him when he applied for the police job.
"He will never be forgotten," McPike said.
Whenever a difficult situation arose, McPike said Swasey was willing to go. Swasey's wife Rachel told McPike she knew there was no way her husband wouldn't respond to the shooting.
"He knew the risks," McPike said. "And he loved what he did."
Though he was passionate about serving as an officer, Swasey would not want to be defined only by his profession, said Kurt Aichele, a pastor at Hope Chapel.
Swasey saw himself first as a follower of Jesus Christ, and his faith inspired his love of his family and service to his community, Aichele said.
Swasey was one of Aichele's closest friends — the two men had known each other for 10 years — and the loss was a difficult one.
"Yet I celebrate that tonight Garrett is united with Christ," Aichele said.
Aichele and fellow pastor Dontanville prayed for the community and also for forgiveness of the gunman.
"Garrett would tell you tonight that forgiveness extends to him," Dontanville said.
At a gathering earlier in the day, he and other church members prayed with Rachel Swasey. She reminded them that her husband was in heaven.
"It's the beginning of his watch," Dontanville said, shaking his head at the traditional phrase, "end of watch," used to honor fallen police officers. "It didn't end here for him."
Stephanie McNeal, Adolfo Flores, and David Mack contributed to this report.