Michael Ford is only 22, but he recorded his last will and testament in a cellphone video and then headed to the Landover, Md., police station on a quiet Sunday afternoon to die, police said.

Ford fired randomly at an ambulance, other vehicles and the doors of the station, pinning down officers who poured from the station to confront him, police said. Two of his brothers stood nearby recording the ambush with cellphones as it unfolded moment by agonizing moment.

Amid that barrage, an off-duty detective, Jacai Colson, arrived to visit another officer. Colson sprang from an unmarked police car and “heroically” drew Ford’s fire as he exchanged shots with the gunman, the police chief said.

The move allowed officers to overcome Ford, but in a chaotic moment, a shot probably fired by one of Colson’s fellow officers struck him and ultimately took his life.

Colson, an undercover narcotics detective, was in street clothes. It is unclear whether the officer who shot Colson confused him with an assailant or whether Colson was wounded accidentally amid the chaotic gunfire, Prince George’s County Police Chief Henry Stawinski III said.

Three Prince George's County brothers are being held in connection with the fatal shooting of Officer Jacai Colson in Landover March 13. Police said on Monday that Colson was likely killed by friendly fire. Here's what we know so far. (Victoria Walker/The Washington Post)

Stawinski expressed anger and incredulity Monday as he relayed the story of how the four-year police veteran lost his life and a man who intended to take his own life by drawing police fire had survived.

Colson’s parents stood at the chief’s news conference, arm-in-arm nearby, leaning on each other for support.

When asked why Ford would carry out an attack on a police station while his brothers recorded the death of an officer, Stawinski said there was no answer.

“This is about nothing,” Stawinski said. “It was unprovoked. Michael had a history of mental illness. But what is more troubling to me is that anybody could stand by so callously and do nothing.”

County prosecutors were preparing charges against the brothers.

Stawinski said Ford, who was shot during the incident and is still at a hospital, and his two brothers would face 21 charges for the baffling and coldblooded attack, including conspiracy, second-degree murder and attempted first-degree murder. Police said the Ford brothers did not work with any outside groups and hatched the plan on their own.

Police said the suspects are Michael DeAndre Ford, 22, of Landover, and his brothers, Malik Ford, 21, of Fort Washington and Elijah Ford, 18, of Landover. Ford’s relatives said he suffered from bipolar disorder and had a run-in with police in South Carolina a day before the shooting.

Stawinski lauded Colson, 28, who was honored solemnly across Maryland and the nation Monday. Colson is one of a number of police officers shot in recent months.

Stawinski said the tragedy was all the more painful because Colson was probably shot by another officer. He described the officers involved as “devastated.”

Police released chilling images of the scene, screenshots of the video that Michael Ford’s brothers recorded during the gun battle. One image shows Michael Ford pointing a gun at someone crouched behind a police van, while a brother reflected in the rearview mirror sits in the safety of a car, capturing the terror.

The brothers had a conversation about the ambush at 4:17 p.m. Sunday, and Michael Ford recorded his final message, police said. Police did not describe what he said, but shortly after 4:30 p.m., the shooting began on Barlowe Road.

The younger brothers drove Michael Ford to the police station before he got out and fired. the chief said. During the firefight, he shot at two SUVs and a passing ambulance, police said.

Through it all, at least one of his brothers sat in a red car and watched, recording the incident.

“He’s got a gun!” one of the emergency medical technicians riding in the ambulance said when he saw Michael Ford, according to Prince George’s Assistant Fire Chief Alan Doubleday. As the ambulance driver made a hard right turn, Ford fired, Doubleday said. The shot nicked the bumper.

Michael Ford fired some shots at officers and the door of the police station to draw a response from officers and lure them out, Stawinski said.

Colson arrived while the shooting was underway. He immediately joined the gun battle, Stawinski said. Colson ran down Barlowe Road east toward Landover Road. Michael Ford followed, and remaining officers chased them, Stawinski said.

“It is in this confusion we believe the errant round struck Detective Colson,” Stawinski said.

Five other officers responded to the shooting, and four of them fired their weapons. The officers who fired showed “incredible restraint” because of homes and passing cars in the busy area, Stawinski said.

It is not the first time a county officer has been killed by friendly fire. The department said one of its officers was struck by a bullet fired from another officer’s gun decades ago.

Stawinski was particularly upset that Michael Ford’s brothers did nothing to stop him.

“They knew in advance,” Stawinski said. “They had every opportunity to call 911. They had every opportunity to do something. They did nothing.”

An aunt of the three suspects, Shante Ramos, 30, said on Monday that Michael Ford suffers from bipolar disorder and has been battling mental illness all of his life. “We have no idea what sparked this,” she said. Ramos confirmed that Michael was the one who was shot, but she said relatives have been unable to see him and they do not have details about his injuries.

“We can’t believe this is happening,” said Ramos, who lives in Northwest Washington. “We are so sad for this officer dying. We have no idea what happened.”

She said that Michael Ford has trouble when he is off his medication and that he was homeless for a time in Montgomery County. She said he and his brothers were raised by her sister, Lisa, a single mother who had five children.

“We didn’t see any of this happening,” Ramos said. “They’re saying Michael wanted to kill himself. We just don’t know.” She said that Michael Ford’s mother suffered a heart attack after police in Prince George’s burst into her house to search it following the shooting and that she is now at the same hospital as her son.

A spokesman for the Greenville County (S.C.) Sheriff’s Office said there was a warrant out for a misdemeanor domestic-violence charge against Michael Ford. The spokesman said Ford was accused of punching a woman several times about 1 a.m. Saturday in Greenville. It was unclear what transpired after that incident and before the shooting in Maryland.

It wasn’t the first time Michael Ford had been in trouble.

Michael Ford had run-ins with police in Montgomery. He took four pairs of jeans from a department store in Wheaton in 2013, a case that was dropped after he agreed to perform 24 hours of community service. He was accused of marijuana-dealing and illegal gun possession, charges he was acquitted of at trial.

Documents and audio recordings in the cases capture some of Michael Ford’s legal and personal struggles from 2009 to 2013. Much of that time he was homeless, he said.

“I got put out when I was 16,” Ford testified. “I was forced to basically live on the street.”

When he was 18, Ford said on the witness stand, he stole a person’s cellphone in Washington, pleaded guilty to attempted robbery and was placed on probation. “I was trying to take the phone and sell it so I could probably get a hotel for the night to sleep in,” he said.

During the news conference Monday, when John Teletchea, president of the county police union local, spoke about how Colson, the slain officer, could light up a room, Colson’s mother quietly interjected, “He has.”

Teletchea denounced the alleged acts of the Ford brothers.

“We have individuals videotaping them as if it’s a game, as if it is something we’re going to put on YouTube and glorify,” Teletchea said.

Dan Morse, Arelis R. Hernández, Keith L. Alexander, Clarence Williams, Derek Hawkins, Matt Zapotosky, Julie Tate, Jennifer Jenkins and Ovetta Wiggins contributed to this report.